This circuit functions to remotely monitor Pls help a couple of electric heaters have been left on. Its sensors must be placed in contact with the feeders to be Able to monitor Pls the power cable is drawing current, Thus causing the circuit to a switch-on LED. The circuit and its coil sensor Can be placed very far from the actual load, provided an easy access to the power cable is available.
Any type of high-current load or group of loads Can be monitored, eg: heaters, motors, washing machines, dish-washers, electric ovens. Etc., provided they want dissipate a power comprised in the 0.5 at least - 1KW range. This design features three versions. The basic one illuminates a LED Pls the load is on. The second version Pls drives a relay a pre-set current value flows into the power cable. The third version Pls D7 switches-on the load power is about 1KW, D6 Pls the load power is about 2KW and D5 Pls the load power is about 3KW
Any type of high-current load or group of loads Can be monitored, eg: heaters, motors, washing machines, dish-washers, electric ovens. Etc., provided they want dissipate a power comprised in the 0.5 at least - 1KW range. This design features three versions. The basic one illuminates a LED Pls the load is on. The second version Pls drives a relay a pre-set current value flows into the power cable. The third version Pls D7 switches-on the load power is about 1KW, D6 Pls the load power is about 2KW and D5 Pls the load power is about 3KW
Notes:
- The pick-up coil L1 is a common 10mH miniature inductor. This inductor must be placed tightly against one wire of the power cable, leaving the other wire some centimeters apart.
- The sensitivity will be doubled if the inductor is placed tightly between the two wires as shown in the diagram, top left. On the contrary, do not place the inductor against paired wires as the signal tends to cancel and the circuit will not work.
- The LED limiting resistor R5 should have a value comprised in the 100R - 1K range, depending on the output voltage obtained.
- LED D1 and its limiting resistor R5 can be omitted in versions two and three of the circuit.
List Component
R1,R2,R8____________1K 1/4W Resistors
R3,R4_____________220K 1/4W Resistors
R5________________100R 1/4W Resistor
R6_________________10K 1/2W Trimmer
R7,R10______________1M 1/4W Resistors
R9_________________22K 1/2W Resistor
R11 to R17__________1K 1/4W Resistors
C1,C3_____________100Î…F 25V Electrolytic Capacitors
C2,C4_______________1Î…F 63V Electrolytic Capacitors
D1________________5mm. Red LED
D3,D4___________1N4002 100V 1A Diodes
D2,D5,D6,D7_______LEDs (Any color and size)
Q1_______________BC327 45V 800mA PNP Transistor
IC1______________TL061 Low current BIFET Op-Amp
IC1______________LM358 Low Power Dual Op-amp
IC1______________LM324 Low Power Quad Op-amp
L1________________10mH miniature Inductor
RL1______________Relay with SPDT 2A @ 220V switch
Coil Voltage 12V. Coil resistance 200-300 Ohm
J1_______________Two ways output socket
Source