Hello everyone, I am relocating a pair of transmission control levers to a different location within a car. At present each lever actuates a pair of SPST microswitches (at the same time) in a voltage/resistor ladder circuit. The diagram is below:
The outputs from the circuit are up, down, and a standby line which is used to provide fault tolerance. It is connected to a gearbox ECU and the replacement circuit must match exactly the existing voltage outputs.
There are some constraints I must work with in the new location:
- There are two wires between the old location and new. A VBATT and ground do exist in the new location;
- The two levers in the new location each operate a single SPST switch.
I came up with the idea of using the new switches to operate a pair of solid state relays, i.e.:
However this was before I realised there is a voltage drop across the load side of SSRs which means the circuit wouldn't work, because the gearbox ECU would not see the voltages it was expecting.
I am now scratching my head and seeking ideas. Any help appreciated.