Hello all,
I hope you can help. Firstly I would like to state that I am no expert on electronics!
Background;
I am hoping to be able to use a transitor circuit to be able fix a fault on the ignition circuit of my car. From the engine management computor there should be a 12v signal going to a coil at each spark plug (measured using a volt meter from the battery negative and the output from the computor. When the 12volt signal is switched off, controlled by the timing in the computor. i assume that high tension spark is created by coil as the field collapses. This is true for 3 of the 4 spark plugs but 1 of them is only showing a signal of 0.3volts and i am not getting a spark at the plug. I suspect that a transistor has broken in the computor. I am not able to get inside the computer to fix the actual transistor. Replacing the computor costs more than I am prepared to spend on the car.
Question:
*What I would like to do, is take the signal that is coming from the wire coming out of the computor (0.3 volts) and use this to switch in a 12volt feed. So, when the 0.3volts is present i want a single wire coming out of my new circuit to have a 12 volt signal that I can connect back to the coil and when the 0.3 volt signal does not exist I would like no output from the circuit to switch off. I believe that current required on the output side it about 5 amps. I seem to recall that transitors can be used as switches in this way, but in the diagrams I have seen for NPN transistors the load sits between the 12volt supply and one of the pins of the transistor. This would be fine if I had the two ends of the load component to connect, such as the two connecters for a bulb. But I don't I only one signal cable?
Is any one able to suggest what circuit I need to achieve my goal? I just can't get my head round it! Any assistance greatly appreciated.
Kind regards
Dom**
I hope you can help. Firstly I would like to state that I am no expert on electronics!
Background;
I am hoping to be able to use a transitor circuit to be able fix a fault on the ignition circuit of my car. From the engine management computor there should be a 12v signal going to a coil at each spark plug (measured using a volt meter from the battery negative and the output from the computor. When the 12volt signal is switched off, controlled by the timing in the computor. i assume that high tension spark is created by coil as the field collapses. This is true for 3 of the 4 spark plugs but 1 of them is only showing a signal of 0.3volts and i am not getting a spark at the plug. I suspect that a transistor has broken in the computor. I am not able to get inside the computer to fix the actual transistor. Replacing the computor costs more than I am prepared to spend on the car.
Question:
*What I would like to do, is take the signal that is coming from the wire coming out of the computor (0.3 volts) and use this to switch in a 12volt feed. So, when the 0.3volts is present i want a single wire coming out of my new circuit to have a 12 volt signal that I can connect back to the coil and when the 0.3 volt signal does not exist I would like no output from the circuit to switch off. I believe that current required on the output side it about 5 amps. I seem to recall that transitors can be used as switches in this way, but in the diagrams I have seen for NPN transistors the load sits between the 12volt supply and one of the pins of the transistor. This would be fine if I had the two ends of the load component to connect, such as the two connecters for a bulb. But I don't I only one signal cable?
Is any one able to suggest what circuit I need to achieve my goal? I just can't get my head round it! Any assistance greatly appreciated.
Kind regards
Dom**