Light/Dark Switch With Relay

The circuit as shown act as a light detector. Under normal conditions the resistance of the LDR is high, keeping pin 2 low. When light falls onto the LDR the resistance drops to a couple hundred ohms and triggers pin 2 high which biases the base of Q1 via pin 6 and R4 and in turn activates the relay.

Light/Dark switch Circuit with relay

As you may have notice, the 741 is connected as a voltage comparator. Two voltage dividers are easy to be found: The first one is the10K resistor and the LDR . The second one is composed by the two 470 Ohms resistors and the potentiometer. Both the outputs of the dividers are connected as inputs to the voltage comparator.

The second voltage divider will settle the reference voltage. The first voltage comparator that contains the LDR, will change it's voltage according to the light level. When the voltage across the negative input of the comparator is less than the voltage to the positive input of the comparator, the output is held low. When the voltage on the negative input rises, there will be a time that it becomes greater than or equal to the positive (pre-selected) voltage, and then the output becomes high and the relay through the 2N2222 is actuated.

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Simple switch-Off Time Delay Circuit

Designing a switch off delay circuit is quite simple and will cost you no more than $5 to make. All parts can be picked up from Radio Shack or Fry's if you have them as well as Parts Express. This will cover the mechanical aspects of it - theoretical topics can come later. If you suffer from pops on your amps or any other components, this will help you eliminate it, but it does not work in all cases.

Simple switch-Off Time Delay Circuit

Designing a swictch off delay circuit is quite simple and will cost you no more than $5 to make. All parts can be picked up from Radio Shack or Fry's if you have them as well as Parts Express. This will cover the mechanical aspects of it - theoretical topics can come later. If you suffer from pops on your amps or any other components, this will help you eliminate it, but it does not work in all cases.

The two circuits di atas illustrate opening a relay contact a short time after the ignition or ligh switch is turned off. The capacitor is charged and the relay is closed when the voltage at the diode anode rises to 12 volts. The circuit on the left is a common collector or emitter follower and has the advantage of one less part since a resistor is not needed in series with the transistor base. However the voltage across the relay coil will be two diode drops less than the supply voltage, or about 11 volts for a 12.5 volt input. The common emitter configuration on the right offers the advantage of the full supply voltage across the load for most of the delay time, which makes the relay pull-in and drop-out voltages less of a concern but requires an extra resistor in series with transistor base. The common emitter (circuit on the right) is the better circuit since the series base resistor can be selected to obtain the desired delay time whereas the capacitor must be selected for the common collector (or an additional resistor used in parallel with the capacitor).

The time delay for the common emitter will be approximately 3 time constants or 3*R*C. The capacitor/resistor values can be worked out from the relay coil current and transistor gain. For example a 120 ohm relay coil will draw 100 mA at 12 volts and assumming a transistor gain of 30, the base current will be 100/30 = 3 mA. The voltage across the resistor will be the supply voltage minus two diode drops or 12-1.4 = 10.6. The resistor value will be the voltage/current = 10.6/0.003 = 3533 or about 3.6K. The capacitor value for a 15 second delay will be 15/3R = 1327 uF. We can use a standard 1000 uF capacitor and increase the resistor proportionally to get 15 seconds.

Source: bowdenshobbycircuits.info

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Simple Switch On Time Delay Circuit

This Switch On Time Delay circuit has been designed to create a lamp switch operated electronically with an option of setting a delay in the time of execution of operation to reduce one or more lamps in a stairwell or any other places where this circuit may be useful. The circuit can be useful to control various lamp or appliances that can be connected in relay contacts.

Simple Switch On Time Delay Circuit

The circuit that takes advantage of the emitter/base breakdown voltage of an ordinary bi-polar transistor. The reverse connected emitter/base junction of a 2N3904 transistor is used as an 8 volt zener diode which creates a higher turn-on voltage for the Darlington connected transistor pair. Most any bi-polar transistor may be used, but the zener voltage will vary from about 6 to 9 volts depending on the particular transistor used. Time delay is roughly 7 seconds using a 47K resistor and 100uF capacitor and can be reduced by reducing the R or C values. Longer delays can be obtained with a larger capacitor, the timing resistor probably shouldn't be increased past 47K. This Switch On Time Delay circuit should work with most any 12 volt DC relay that has a coil resistance of 75 ohms or more. The 10K resistor connected across the supply provides a discharge path for the capacitor when power is turned off and is not needed if the power supply already has a bleeder resistor.

Sumber: http://www.bowdenshobbycircuits.info

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9 Second Countdown Power-On Relay With 7 segment Display

9 Second Countdown Power-On Relay Circuit

This circuit provides a 9 second delay using a 7 segment display. When the switch is closed, the CD4010 up/down counter is preset to 9 and the 555 timer is disabled with the output held high. When the switch is opened, the timer produces an approximate 1 second clock signal, decrementing the counter until the 0 count is reached. When the zero count is reached, the 'carry out' signal at pin 7 of the counter moves low, energizing the 12 volt relay and stopping the clock with a low signal on the reset line (pin 4). The relay will remain energized until the switch is again closed, resetting the counter to 9. The 1 second clock signal from the 555 timer can be adjusted slightly longer or shorter by increasing or decreasing the resistor value at pin 3 of the timer.

Note:

• The circuit can be powered from a 9V PP3 battery or 12V DC power supply.
• The time delay can be varied by replace the resistor value at pin 3 IC555.
• The push button switch is for starting the timer.
• The appliance can be connected via contacts relay.

Source: bowdenshobbycircuits.info

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Driver Relay Menggunkan Transistor

Basic Transistor relay driver

Bipolar transistor is a component that works based on the presence or absence of flow in the foot triggers the base. In the relay driver applications, the transistor works as a switch that at the time did not accept the current triggers, then the transistor will be in the position of the cut-off and does not conduct current, Ic = 0. And when the base receives the flow triggers, then the transistor will turn into a state of saturation and delivers current. The following is a practical circuit of relay drivers that are reliable for use in microcontroller projects.

Skema Rangkaian Driver Relay
Menggunkan Transistor

The circuit on the left is a common collector or emitter follower and has the advantage of one less part since a resistor is not needed in series with the transistor base. However the voltage across the relay coil will be two diode drops less than the supply voltage, or about 11 volts for a 12.5 volt input.

The common emitter configuration on the right offers the advantage of the full supply voltage across the load for most of the delay time, which makes the relay pull-in and drop-out voltages less of a concern but requires an extra resistor in series with transistor base. The common emitter (circuit on the right) is the better circuit since the series base resistor can be selected to obtain the desired delay time whereas the capacitor must be selected for the common collector (or an additional resistor used in parallel with the capacitor).

The time delay for the common emitter will be approximately 3 time constants or 3*R*C. The capacitor/resistor values can be worked out from the relay coil current and transistor gain. For example a 120 ohm relay coil will draw 100 mA at 12 volts and assumming a transistor gain of 30, the base current will be 100/30 = 3 mA. The voltage across the resistor will be the supply voltage minus two diode drops or 12-1.4 = 10.6. The resistor value will be the voltage/current = 10.6/0.003 = 3533 or about 3.6K. The capacitor value for a 15 second delay will be 15/3R = 1327 uF. We can use a standard 1000 uF capacitor and increase the resistor proportionally to get 15 seconds.

Source: bowdenshobbycircuits.info

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220 Volt Disco Lamp circuit

This disco lamp circuit is not a voice operated switch (VOX) because this circuit is too dumb to differentiate between musical sound or human voice. This is rather a sound activated than voice activated. One interesting application is to control your disco lighting automatically by the musical sound from high power amplifier, when the music signal is dominating the sound space. The disco lamp circuit schematic diagram is shown below.

You can use either moving coil microphone or condenser microphone for this circuit. Make sure the electrolytic capacitor is rated for 16 volt or more. The potentiometer shown in the schematic diagram is used to adjust the gain of the pre-amplification. You can adjust this potentiometer to get a proper sound level where the relay would be activated.

List Componet Of Disco Lamp circuit

• R1 : 22k 1/4 watt resistor
• R2 : 4K7 watt resistor
• R3 : 2K2 watt resistor
• R4,R8 : 10K watt resistor
• R5 : 33K watt resistor
• R6 : 56K watt resistor
• R7 : 1M watt resistor
• Potensio: 50K
• C1 : 470uf/35V electrolytic capacitor
• C2 : 22n ceramic capacitor
• C3 : 100n ceramic capacitor
• C4 : 1Uf/50V electrolyticcapacitor
• D1 - D5 : 1N4007
• D6 : Zener 5.1v
• D7 : 1N4148
• IC : CD 4069
• SCR : FIR 3D
• Mic : Mic Condensor

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Rangkaian Toggle Switch With Relay

This circuit will energize and de-energize a relay at the push of a button. Any type of momentary action push-to-make switch can be used. Pushing the button once - will energize the relay. And pushing it a second time - will de-energize the relay

Skema Rangkaian Toggle Switch

I've drawn the circuit with a single pole relay. But you can use a multi-pole relay if it suits your application. Only one half of the Cmos 4013 is used. So you could construct two independent toggle switches with a single IC. The circuit will work at anything from 5 to 15-volts. All you need do is select a relay with a coil voltage that suits your supply.

The LED provides a visual indication that the relay is energized. In effect - it tells you whether the switch is on or off. It's not necessary to the operation of the circuit. If you wish you may leave out R3 and the LED.

Source: http://www.zen22142.zen

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Rangkaian Radar Pompa Air (Kontrol Ketinggian Air)

Radar Pompa Air (Kontrol Ketinggian Air)

By means of a Relay, employed to drive a water pump, this circuit provides automatic level control of a water reservoir or well.

Skema Rangkaian Radar Pompa air

Note:

• The two steel rods must be supported by a small insulated (wooden or plastic) board.
• The circuit can be used also with non-metal tanks, provided a third steel rod having about the same height of the tank will be added and connected to the circuit's negative ground.

The shorter steel rod is the "water high" sensor, whereas the longer is the "water low" sensor. When the water level is below both sensors, IC1C output (pin #10) is low; if the water becomes in contact with the longer sensor the output remains low until the shorter sensor is reached. At this point IC1C output goes high, Q1 conducts, the Relay is energized and the pump starts operating.

Now, the water level begins to decrease and the shorter sensor will be no longer in contact with the water, but IC1C output will be hold high by the signal return to pin #5 of IC1B, so the pump will continue its operation. But when the water level falls below the longer sensor, IC1C output goes low and the pump will stop.

SW1 is optional and was added to provide reverse operation. Switching SW1 in order to connect R3 to pin #11 of IC1D, the pump will operate when the reservoir is nearly empty and will stop when the reservoir is full. In this case, the pump will be used to fill the reservoir and not to empty it as in the default operating mode.

List Component

• R1,R2: 15K 1/4W Resistors
• R3: 10K 1/4W Resistor
• R4: 1K 1/4W Resistor
• D1: LED
• D2: 1N4148 Diode
• IC1: 4001
• Q1: BC337 NPN Transistor
• SW1: witch
• RL1: Relay with SPDT 2A @ 230V switch, Coil Voltage 12V

source

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Fuse|Sekring Elektronika.

Rangkaian Fuse Elektronika

Circuit of fuse (sekring) electronic designed to operate on 230V AC with an adjustable trip current. When the current through the load exceeds a level determined by the position of the wiper on the 1k wire-wound pot, this circuit cuts off the load immediately. If S1 is open, the range is approximately 300-650 mA, and 0.8-2A when it is closed.

Skema rangkaian fuse|sekring elektronika

Note:

• This circuit connects directly to 220-230V AC which can be lethal! Please do not attempt to build any of the circuits/projects unless you have the expertise, skill and concentration that will help you avoid an injury.
• D1: 1N4001
• T1: TIC225M
• T2: BTA12-600CW

The key variable in the operation of the fuse is the voltage drop across the power resistor(s) which are connected in series with the load. This voltage drop is directly proportional to the current the load draws. When this current is low, the voltage across the resistors is also small and cannot trigger T1. At the same time the gate of T2 is fed from a little power supply built around a negative voltage regulator. T2 is conducting and the load is on.

If the current through the load then gets too high, so that the voltage created across the resistor(s) can trigger the gate of T1 through the 330R resistor and the pot: T1 starts to conduct, swiftly taking away all the current from the gate of T2. The voltage drop across T1 (MT1-MT2) will then be only 0.7 V and T2 will be firmly off. T1 stays this way all until the momentary (normally closed, "push-to-break") Reset push-button is pressed: this causes the current through T1 to drop below the hold level and forces this triac to turn off. Releasing the Reset button re-enables the current flow to and through the gate of T2, switching it on.

Thanks to www.zen22142.zen.co.uk

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Rangkaian Pengendali Kipas Menggunakan Temparatur

Pengendali Kipas Menggunakan Temparatur

This circuit will trigger a relay when a preset temperature is reached. The circuit uses a NTC thermistor with a resistance of 47k at room temperature. The circuit is set in balance by adjusting the the 47k Potentiometer. Any change in temperature will alter the balance of the circuit, the output of the op-amp will change and Energize the relay. Swapping the position of the thermistor and 47k resistor makes a cold or frost alarm.

Skema rangkaian Pengendali kipas menggunakan terparatur

At 25 degrees Celsius a NTC thermistor resistance is approximately 47k. The non-inverting op-amp inputs will then be Roughly half the supply voltage, adjusting the 47k pot should allow the relay to close or remain open. To calibrate the device, the thermistor Ideally needs to be at the required operating temperature. If this is for example, a hot water tank, then the resistance will decrease, one way to do this is use a multimeter on the resistance scale, read the thermistors resistance and then set the preset so that the circuit triggers at this temperature.

Please note that if the temperature then falls, the relay will de-Energize. Temperatures if the environment changes rapidly, then the relay may chatter, as there is no hysteresis in this circuit.

Hysteresis, allows a small amount of "backlash" to be tolerated. With a circuit employing hysteresis, there will be no relay chatter and the circuit will trigger at a defined temperature and require a different temperature to return to the normal state. Hysteresis can be applied to the circuit using feedback, try a 1Meg resistor between the op-amp output, pin 6 and the non-inverting input pin 2 to give the circuit hysteresis.

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Control|Pengendali Relay MenggunakanTransistor

Control (Pengendali) Relay

The following series of functions to control the relay kutup. With an input signal greater than 0.3V pk-pk (100mV RMS) the positive half of the waveform will switch on transistor Q1, and Q2 and the relay. As the input signal switches to its negative transition, Q1 will switch off, but the base current in using-multimeter-to-measure-transistor.html">transistor Q2 continues to flow via the C2, so Q2 and hence load relays remain on. This will happen for any ac signal within 50 to 1000Hz. R1 prevents excessive base current flowing in transistor Q2, if required a series resistor of 100 ohms can be included with C1 to reduce excessive current flow, though this may decrease sensitivity.

Skema rangkaian control (pengendali) Relay

C2 has a dual purpose; as well as smoothing the input signal, it adds a delay to the on / off operation. The delay is dependent on the value of C2 and the coil resistance of the relay. Instead of a relay, a LED and series resistor of 1k could be used instead, however the relay has the advantage of being able to switch large loads on and off. C2 has a dual purpose; as well as smoothing the input signal, it adds a delay to the on / off operation. The delay is dependent on the value of C2 and the coil resistance of the relay. Instead of a relay, a LED and series resistor of 1k could be used instead, however the relay has the advantage of being able to switch large loads on and off.

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Rangkaian Control Relay Menggunakan InfraRed

Control Relay Menggunakan InfraRed

Normally, home appliances are controlled by means of switches, sensors, etc. However, physical contact with switches may be dangerous if there is any shorting. The circuit described here requires no physical contact for operating the appliance. You just need to move your hand between the infrared LED (IR LED1) and the phototransistor (T1).

Skema rangkaian control relay menggunakan infra-red

The infrared rays transmitted by IR LED1 is detected by the phototransistor to activate the hidden lock, flush system, hand dryer or else. This circuit is very stable and sensitive compared to other AC appliance control circuits. It is simple, compact and cheap. Current consumption is low in milliamperes. The circuit is built around an IC CA3140, IRLED1, phototransistor and other discrete components. When regu lated 5V is connected to the circuit, IR LED1 emits infrared rays, which are received by phototransistor T1 if it is properly aligned. The collector of T1 is connected to non-inverting pin 3 of IC1. Inverting pin 2 of IC1 is connected to voltage-divider preset VR1. Using preset VR1 you can vary the reference voltage at pin 2, which also affects sensitivity of the phototransistor. Op-amp IC1 amplifies the signal received from the phototransistor. Resistor R3 controls the base current of transistor BC548 (T2). The high output of IC1 at pin 6 drives transistor T2 to energise relay RL1 and switch on the appliance, say, hand dryer, through the relay contacts. The working of the circuit is simple. In order to switch on the appliance, you simply interrupt the infrared rays falling on the phototransistor through your hand. During the interruption, the appliance remains on through the relay. When you remove your hand from the infrared beam, the appliance turns off through the relay.

Assemble the circuit on any general purpose PCB. Identify the resistors through colour coding or using the multimeter. Check the polarity and pin configuration of the IC and mount it using base. After soldering the circuit, connect +5V supply to the circuit.

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Rangkaian Touch Switch Menggunakan 3 Transistor

Touch Switch Menggunakan 3 Transistor

Here is a series of Touch Switch using only 3 transistors, this touch-based transistor switches can activate a load simply by the user touching a metal plate. It is designed to directly switch a relay to allow it to be used with large loads. As it uses only a few commonly available transistors and a 12V supply, it is ideal for hostile environments where mechanical switches would be damaged. Using a latching relay and two of these circuits, a simple two pad "touch on / touch off" arrangement can be made.

Skema Rangkaian Touch Switch Menggunakan 3 Transistor

The touch pad can be most easily made by cutting a small square of PCB material and then soldering on a single wire. Alternatively, something like a penny glued to a plastic backing will do the job.

As mentioned, a latching relay can be used so that a momentary touch activates the relay and it remains active. To turn off a latching relay, power must be interrupted. So a 2nd circuit with a normal relay can be used to cut power (use the NC contacts on the 2nd circuit). Placed side by side, two touch pads form an "on" and an "off" pad.

List Component

R1_______________ 10 Meg 1/4W Resistor
R2_______________ 47K 1/4W Resistor
R3_______________ 1 120k 1/4W Resistor
R4_______________ 470 Ohm 1/4W Resistor
C1_______________15uF Electrolytic Capacitor
D1_______________ 1N4007 Silicon Rectifier Diode
Q1_______________ 2N5458 N Channel Field Effect Transistor
Q2_______________ 2N2222 NPN Transistor 2N3904
Q3_______________ 2N3906 PNP Transistor
K1_______________ Relay w/12V Coil, Contacts To Suit Application

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Rangkaian Saklar Sentuh

This is a Turn on and turn off your electrical devices using touch switch, so you can “play” your electronic devices more fun. Touch switch don’t need mechanical part, so they will not worn out due to mechanical contact. Touch switches can be used in places where regular switches would not last, such as wet or very dusty areas. You just need to add some relay to switch your devices which require high voltage supply.

Skema rangkaian saklar sentuh

Component list:

C1: 10uF/16V Electrolytic Capacitor
R1, R2: 100K 1/4 Watt Resistor
R3: 10 Meg 1/4 Watt Resistor
U1: 4011 CMOS NAND Gate IC
MISC 1 Board, Wire, Socket For U1


Notes:

• The contacts an be made with just two loops of wire close together, or two squares etched close together on a PC board.
• When activated, the output of the circuit goes high for about one second. This pulse can be used to drive a relay, transistor, other logic, etc.
• You can vary the length of the output pulse by using a smaller or larger capacitor for C1.

IC 4011 Description:

The HEF4011B provides the positive quadruple 2-input NAND function. The HEF4011 have equal source and sink current capabilities and conform to standard B series output drive.
The devices also have buffered outputs which improve transfer characteristics by providing very high gain. All inputs are protected against static discharge with diodes to VDD and VSS.

The HEF4011B Features

Low power TTL: Fan out of 2 driving 74L compatibility: or 1 driving 74LS
5V–10V–15V parametric ratings
Symmetrical output characteristics
Maximum input leakage 1 μA at 15V over full
temperature range.
.

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Rangkaian Driver/Buffer Saklar Relay

This is a circuit instead of a standard on-off switch. Switching (Saklar) is very gentle. If we don’t use the PCB, connect unused input pins to an appropriate logic level (’+’ or ‘-’). Unused output pins *NEED* be left open!. One step ’push’ activates the relay, another ‘push’ de-activates the relay.

Rangkaian Driver/Buffer Saklar Relay pIc

list Component Of Rangkaian Driver/Buffer Saklar Relay
R1 = 10K
R2 = 100K
R3 = 10K
R4 = 220 Ohm (optional)
C1 = 0.1µF, Ceramic (100nF)
C2 = 1µF/16V, Electrolytic
D1 = 1N4001
Led1 = Led, 3mm, red (optional)
Q1 = 2N4401 (see text) IC1 = 4069, CMOS, Hex Inverter (MC14069UB), or equivalent
S1 = Momentary on-switch
Ry1 = Relay

Description

This circuit operate on voltages from 3 to 18 volts, but most applications are in the 5-15 volts. Although the IC1 4069 contains protection circuitry against damage from ESD , use common sense when handling this device. Depending on your application you may want to use an IC-socket with IC1. It makes replacement easy if the IC ever fails. The IC is CMOS so watch for static discharge! You can use any type of 1/4 watt resistors including the metal-film type.

The type for D1 in not critical, even a 1N4148 will work. But, depending on your application I would suggest a 1N4001 as a minimum if your relay type is 0.5A or more. Any one in the 1N400x series diodes will work.

Any proper replacement for Q1 will work, including the european TUN’s. Since Q1 is just a driver to switch the relay coil, almost any type for the transistor will do. PN100, NTE123AP, BC547, 2N3904, 2N2222, 2N4013, etc. will all work for the relays mentioned here. For heavier relays you may need to change Q1 for the appropriate type.

For C2, if you find the relay acts not fast enough, you can change it to a lower value. It is there as a spark-arrestor together with diode D1.

For the relay I used an 8 volt type with the above circuit and a 9 volt battery. Depending on your application, if the current-draw is little, you can use a cheap 5V reed-relay type. Use a 8V or 9V relay type if your supply voltage is 12V. Or re-calculate resistor R3 for a higher value.

The circuit and 9V will work fine and will pull the relay between 7 and 9 volt, the only thing to watch for is the working voltage of C2; increase that to 50V if you use a 12V supply.

The pcb was designed for an Aromat/Omron relay, 12V/5A, #HB1-DC12V. You can easily re-design the relay pads on the PCB for the relay of your choice. If you wish to use something you already have, and you don’t want to re-design the PCB, you can glue the relay up-side-down on the pcb and wire the relay contacts manually to the pcb-holes or directly to your application. Use a 2N2222 transistor for Q1 if your supply voltage is higher than 9V and/or your relay is heavy duty, or doesn’t want to pull-in for any other reason.

Again, the pcb drawing is not to scale. Use ‘page-setup’ to put the scale to 103% for a single pcb, vertically, and your scale should be correct. I use a laser printer and so I don’t know if this scale of 103% is for all printers. To check, print a copy onto regular paper and see if the IC pins fit the print. If so, your copy is correct. If not, change the scale up of down until a hardcopy fits the IC perfectly.

The Led is nice for a visual circuit indication of being ‘on’. For use with 12V supply try making make R4 about 330 ohms. The LED and R4 are of course optional and can be omitted. Your application may already have some sort of indicator and so the LED and R4 are not needed.

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Rangkaian Saklar sentuh Berbasis IC 555

Saklar sentuh Berbasis IC 555

This is the simple circuit of diagram of a small touch using IC NE 555 . This circuit is ideally useful for making touch operated doorbells, buzzers, toys etc which when touched on the touch plate operates the relay for a preset time and the turns off automatically.

the circuit is realized by utilizing the high input impedance of trigger pin of the IC 555. When the IC is triggered by the induced voltage of human body the output goes high for a time determined by R1 and C1. The transistor is used to drive the relay. The relay contacts can be used to drive the load like bell, motor , lights etc.

To setup the circuit connect to power supply and adjust R1 while keeping touching on the touch plate. Stop at the point where relay activates.If relay is in the activated state initially then do the same until the relay is deactivated.

Skema rangkaian saklar sentuh Berbasis IC 555

functions of each pin IC 555

1. Ground, is the input pin of the source of the negative DC voltage
2. trigger, negative input from the lower comparators (comparator B) that maintain oscillation capacitor voltage in the lowest 1 / 3 Vcc and set RS flip-flop
3. output, the output pin of the IC 555.
4. reset, the pin that serves to reset the latch inside the IC to be influential to reset the IC work. This pin is connected to a PNP-type transistor gate, so the transistor will be active if given a logic low. Normally this pin is connected directly to Vcc to prevent reset
5. control voltage, this pin serves to regulate the stability of the reference voltage negative input (comparator A). This pin can be left hanging, but to ensure the stability of the reference comparator A, usually associated with a capacitor of about 10nF to berorde pin groun
6. threshold, this pin is connected to the positive input (comparator A) which will reset the RS flip-flop when the voltage on the capacitor from exceeding 2 / 3 Vc
7. discharge, this pin is connected to an open collector transistor Q1 is connected to ground emitternya. Switching transistor serves to clamp the corresponding node to ground on the timing of certain
8. vcc, pin it to receive a DC voltage supply. Usually will work optimally if given a 5-15V. the current supply can be seen in the datasheet, which is about 10-15mA.

.

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Rangkaian Sekring|Fuse Otomatis

To restrict / security, electric current is usually used fuse/sekring or patron is dissolved when going short (konslet) will drop out and must be replaced with a new one. Then, in order not to drop out of each new change means that more money out to buy, then there fuse/sekring automatically work with the reset button. So there are problems with each short, fuse/sekring will automatic decided flow then to return it does not need to buy a new (if not broken) just press the reset the equipment will live again.

This is one of the simplest electronic fuse circuit one can make. The circuit uses only one transistor, one SCR, one push button switch and two resistors.

Skema Rangkaian Sekring|Fuse Otomatis

The value of R1 can be obtained from the equation; [Imax] X [R1] = 0.7V.
R2 can be obtained from the equation; R2 = [Vs] X [1K Ohms].
Wattage rating of R1 can be obtained from the equation; W = [Imax] X [Imax] X [R1].
For this circuit to work the current consumption of the load must be greater than the holding current of the SCR.

The working of the circuit is very simple. Initially the load current flows through SCR and resistor R1.The value of R1 is so selected that, the maximum load current multiplied by the resistance of R1 is equal to 0.7 volts. When the load current exceeds the maximum value the voltage drop across R1 becomes more than 0.7V and switches transistor Q1 ON. Now the transistor completely bye passes the load current and the current through triac falls below the holding current. This makes the triac OFF. When SCR is OFF there will not be any current flow through R1 and so the voltage across it falls to 0.This makes the transistor OFF, completely isolating the load circuit.The fuse can be resetted by pressing S1.When S1 is pressed the SCR is again triggered and remains latched to conduct the load current.

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Lampu Otomatis Sederhana

Gbr. Rangkaian lampu otomatis

Component list:

• R1 = 100K Pot
• Q1 = 2N3904 or 2N2222
• Q2 =NPN PhotoTransistor
• RELAY= 9V Relay

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Automatic lamp Circuit

This series will work as the lighting will automatically turn on when the voltage net PLN off. If the net voltage on the series will off automatically.

Emergency Light chain scheme can be viewed directly on the image above


Components list:

R1 R2 C1 D1,D2 S1 Tr1 Trafo L1,l2 Batery

: 33 Ohm : 470 Omh : 470 uF/16v : 1n4001 : switch (push on push off) : BC 160 or BC 143 : 4,5 volt 200 mA : lamp 2,5 volt : NiCd 2x1,25 volt 2-4 Ah

Series of automatic lighting unit is very simple. Voltage electricity from the net PLN revealed by transformer Tr1 and change in DC with half-wave system by dioda D1 and capacitor C1.

Next portion 6 Volt DC is used to fill the 2 Ni-Cad Battery through R1 and D2 with a continuous flow of about 100 mA (charging current to a safe a Ni-Cad battery 2 Ah).

reverse bias between the base of emitor transistors T1 obtained from the voltage fall on the D2 will make transistors T1 does not work so that lamp will be off. When voltage net PLN suppressed, T1 base transistors will be biased flow through R2, transistors T1 will work and lamp on.

When the voltage net PLN entry, transistors T1 will does not work, the lamp will be off and the battery charged through R1 and D2

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