Hi all,
I need a little help with this circuit.
Basically I want to ditch some electronics within an existing touchpad that got wet and just use the touch pad contacts to drive a transistor to drive a remote mounted relay. space inside the touchpad is very limited so it has to be simple.Relay should only operate when touchpad is pressed.
Specs are as follows,
1) Relay is 75 Ohm 12V permanently fed by 12V+ and grounded by touchpad
2) I just want simple 2 wires going to touchpad i.e. pad to ground transistor base when pressed which will ground the relay.
I have decided to use a TIP32C PNP as the driver transistor, but am having some trouble biasing it and it tends to lock on.
I think this is due to the emitter going to ground when the transistor turns on.
Any ideas anyone?
I need a little help with this circuit.
Basically I want to ditch some electronics within an existing touchpad that got wet and just use the touch pad contacts to drive a transistor to drive a remote mounted relay. space inside the touchpad is very limited so it has to be simple.Relay should only operate when touchpad is pressed.
Specs are as follows,
1) Relay is 75 Ohm 12V permanently fed by 12V+ and grounded by touchpad
2) I just want simple 2 wires going to touchpad i.e. pad to ground transistor base when pressed which will ground the relay.
I have decided to use a TIP32C PNP as the driver transistor, but am having some trouble biasing it and it tends to lock on.
I think this is due to the emitter going to ground when the transistor turns on.
Any ideas anyone?
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