100Watt Inverter Circuit by IRF44 Mosfet

This inverter circuit will provide a very stable 230V Output Voltage. Frequency of operation is determined by a VR1 and is normally set to 60 Hz. Various “off the shelf” transformers can be used. Or Custom wind your own for best results. Additional MosFets can be paralleled for higher power. It is recommended to Have a “Fuse” in the Power Line and to always have a “Load connected”, while power is being applied. The Fuse should be10 Amps per 100 watts of output. The Power leads must be heavy enough wire to handle this High Current Draw

Skema Rangkaian 100Watt Inverter by IRF44 Mosfet

Absolute Maximum Ratings of IRF44 Mosfet

• Continuous Drain Current (25°C, 10V) = 49 A
• Continuous Drain Current ( 100°C, 10V) = 35 A
• Pulsed Drain Current = 160 A
• Power Dissipation = 94 W
• Gate-to-Source Voltage = ± 20 V
• Avalanche Current = 25 A
• Operating Junction = -55 to + 175

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12VDC to 220VAC Inverter Circuit Using IC 555

This is a simple 12VDC to 220AC inverter circuit that can be used produces an AC output at line frequency and 220AC or different voltage by selecting transformer T1. The 555 IC is configured as a low-frequency oscillator, tunable over the frequency range of 50 to 60 Hz by Frequency potentiometer R4.

12VDC to 220VAC Inverter Circuit

The 555 feeds its output (amplified by Q1 and Q2) to the input of transformer T1, a reverse-connected filament transformer with the necessary step-up turns ratio. Capacitor C4 and coil L1 filter the input to T1, assuring that it is effectively a sine wave. Adjust the value of T1 to your voltage. The output ( in watts) is up to you by selecting different components.

Input voltage is anywhere from +5V to +15Volt DC, adjust the 2700uF cap's working voltage accordingly. Replacement types for Q1 are: TIP41B, TIP41C, NTE196, ECG196, etc. Replacement types for Q2 are: TIP42B, TIP42C, NTE197, ECG197, etc.

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Smoke Detector circuit Using LDR

This is a simple Smoke Detector circuit based on a LDR and lamp pair for sensing the fire. It uses a very simple approach to detecting smoke in the air. The alarm works by sensing the smoke produced during fire. The circuit produces an audible alarm when the fire breaks out with smoke.

Smoke Detector circuit using LDR

When there is no smoke the light from the bulb will be directly falling on the LDR.The LDR resistance will be low and so the voltage across it (below .6V).The transistor will be OFF and nothing happens. When there is sufficient smoke to mask the light from falling on LDR, the LDR resistance increases and so do the voltage across it.Now the transistor will switch to ON.This gives power to the IC1 and it outputs 5V.This powers the tone generator IC2 to play a music.This music will be amplified by IC3 to drive the speaker.

The diode D1 and D2 in combination drops 1.4 V to give the rated voltage (3.5V ) to UM66 .UM 66 cannot withstand more than 4V.

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Car Parking Sensor circuit Using Infra-Red LED

This circuit can be used for an assist in parking the car near the garage wall backing up Pls. LED D7 illuminates Pls bumper-wall distance is about 20 cm., D7 + D6 illuminate at about 10 cm. and D7 + D6 + D5 at about 6 cm. In this manner you are alerted Pls approaching too close to the wall.

Car Parking Sensor circuit

All distances mentioned before can vary, depending on infra-red transmitting and receiving LEDs used and are mostly affected by the color of the reflecting surface. Black surfaces lower greatly the device sensitivity. Obviously, you can use this circuit in other applications like liquids level detection, proximity devices etc.

Note:

• The infra-red Photo Diode D2, should be of the type incorporating an optical sunlight filter: these components appear in black plastic cases. Some of them resemble TO92 transistors: in this case, please note that the sensitive surface is the curved, not the flat one.
• Avoid sun or artificial light hitting directly D1 & D2.
• If your car has black bumpers, you can line-up the infra-red diodes with the (mostly white) license or number plate.
• It is wiser to place all the circuitry near the infra-red LEDs in a small box. The 3 signaling LEDs can be placed far from the main box at an height making them well visible by the car driver.
• The best setup is obtained bringing D2 nearer to D1 (without a reflecting object) until D5 illuminates; then moving it a bit until D5 is clearly off. Usually D1-D2 optimum distance lies in the range 1.5-3 cm.

List Component of Car Parking Sensor circuit:

R1             : 10K
R2,R5,R6,R9    : 1K
R3             : 33R
R4,R11         : 1M
R7             : 4K7
R8             : 1K5
R10,R12-R14    : 1K
C1,C4          : 1µF/63V
C2             : 47pF
C3,C5          : 100µF
D1             : Infra-red LED
D2             : Infra-red Photo Diode (see Notes)
D3,D4          : 1N4148
D5-7           : LEDs (Any color and size)
IC1            : NE555
IC2            : LM324
IC3            : LM7812 

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UM3561 - Simple Sound Effects Generator Circuit

This is a very simple. The IC UM3561 produces four differen sound effects, the output at Pin 3 being amplified by the transistor 2N2222. A 64 ohm loudspeaker can be substituted in place of the 56 ohm resistor and 8 ohm loudspeaker.

Skema Rangkaian Sound Effects Generator

The 2 pole 4 way switch controls the sound effects. Position 1 (as drawn) being a Police siren, position 2 is a fire engine sound, 3 is an ambulance and position 4 is a machine gun effect.

Note:
The IC sound generator UM3561 is now available in a kt from Maplin Electronics. Click here for the link.

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Op-Amp 6-Line Audio Mixer Circuit

As with any audio mixer circuit, a slight loss is always introduced. The final summing amplifier has a gain of 2 or 6dB to overcome this. The Input line level should be around 200mV RMS.

Skema Rangkaian 6-Line Audio Mixer based Op-Amp

The mic inputs are amplified about 100 times or 40dB, the total gain of the mixer including the summing amplifier is 46dB. The mic input is designed for microphones with outputs of about 2mV RMS at 1 meter. Most dynamic microphones meet this standard.

The choice of IC op-amp is not critical in this circuit. Bipolar, FET input or MOS type op-amps can therefore be used; i.e 741, LF351, TL061, TL071, CA3140 etc. The power supply is a dual positive and negative supply, two 9 Volt batteries may be used as shown above or a power supply is recommended for longer periods of use

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