I'm struggling a bit with a 12v DC project.
I have a 12 volt hydraulic pump motor with three wires: two for v+ and one for ground. The motor is reversible depending on which wire receives the V+. It is controlled by a SPDT switch.
The hydraulic pump has a high pressure and a low pressure circuit (think hydraulic motor used to raise / lower a boat's outdrive trim.) Originally, mechanical relay contactors and various micro limit switches were used to control the 50 amp load. I'd like to use solid state hydraulic pressure sensors and solid state relays.
I have a pretty limited (very little) background in electronics. I know the basics, but obviously am missing something, as I can't quite get this circuit to work.
With the hydraulic motor load wires disconnected, the circuit works- low pressure is sensed and that causes the low pressure sensor to close, energizing the appropriate SSR. The SSR's LED illuminates- and it's output circuit is closed, all as expected.
And further testing with the hydraulic motor connected into the SSR's output, if the SSR is activated with power on the inputs, it works- the SSR LED illuminates, and the pump motor operates as expected.
But when the pressure switch is connected to the SSR input, and the hydraulic motor is wired into the SSR's output, the circuit will pulse on and off about twice per second. The motor doesn't run under this condition.
The attached image shows how I've wired this. I'm ready to redo the circuit if someone can show me the light.... Anyone?
Thanks a lot!
Peter
I have a 12 volt hydraulic pump motor with three wires: two for v+ and one for ground. The motor is reversible depending on which wire receives the V+. It is controlled by a SPDT switch.
The hydraulic pump has a high pressure and a low pressure circuit (think hydraulic motor used to raise / lower a boat's outdrive trim.) Originally, mechanical relay contactors and various micro limit switches were used to control the 50 amp load. I'd like to use solid state hydraulic pressure sensors and solid state relays.
I have a pretty limited (very little) background in electronics. I know the basics, but obviously am missing something, as I can't quite get this circuit to work.
With the hydraulic motor load wires disconnected, the circuit works- low pressure is sensed and that causes the low pressure sensor to close, energizing the appropriate SSR. The SSR's LED illuminates- and it's output circuit is closed, all as expected.
And further testing with the hydraulic motor connected into the SSR's output, if the SSR is activated with power on the inputs, it works- the SSR LED illuminates, and the pump motor operates as expected.
But when the pressure switch is connected to the SSR input, and the hydraulic motor is wired into the SSR's output, the circuit will pulse on and off about twice per second. The motor doesn't run under this condition.
The attached image shows how I've wired this. I'm ready to redo the circuit if someone can show me the light.... Anyone?
Thanks a lot!
Peter
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