Hi
I'm new here but hoping someone can help.
I haver two small 5v pull solenoids connected to an arduino board via a TIP 102 power darlington pair with integral diode.
The arduino activates the solenoids for a preset time determined by the programme. All works fine and the solenoids activate correctly. However when the TIP 102 is turned off the solenoids stick pulled in. If you tap the ends they return normally. At first I thought this was a mechanical problem but it's not as the solenoids don't stick when not first energised. I thought there may be a problem with the circuitry so I connected the solenoids directly to the arduino's 5V supply line driven from the USB on my computer but they still stick open - sometimes not all the time. They still stick open when disconnected from the supply and even when you short the terminals of the solenoids they still stay pulled in. It is as if there is residual magnetism holding in the plungers?
This is really making me pull my hair out as everything else works fine except these damn things.
Anyone got any ideas?
Tony
I'm new here but hoping someone can help.
I haver two small 5v pull solenoids connected to an arduino board via a TIP 102 power darlington pair with integral diode.
The arduino activates the solenoids for a preset time determined by the programme. All works fine and the solenoids activate correctly. However when the TIP 102 is turned off the solenoids stick pulled in. If you tap the ends they return normally. At first I thought this was a mechanical problem but it's not as the solenoids don't stick when not first energised. I thought there may be a problem with the circuitry so I connected the solenoids directly to the arduino's 5V supply line driven from the USB on my computer but they still stick open - sometimes not all the time. They still stick open when disconnected from the supply and even when you short the terminals of the solenoids they still stay pulled in. It is as if there is residual magnetism holding in the plungers?
This is really making me pull my hair out as everything else works fine except these damn things.
Anyone got any ideas?
Tony