Hi, I am currently trying to build a trailcam for watching wildlife with using a Picaxe controller. I have written the program and everything works just fine. I initually tried switching the camera power / shutter using npn transistors but because of the weird way the camera buttons work, this didnt seem to work, and kept on sending the camera crazy. So I hooked them up to two 5v relays and this works just fine. The problem is when the shutter / power is going off all you hear is click click click click, so not really the stealthy setup I was looking for as I think it would scare the animals off, so I have been looking at alternatives.
I have purchased off ebay some of these relays, they are really tiny an quiet, the problem is I didnt realise they were latching relays, so once the power is switched I cant get the damn thing to turn back off again without reversing the polarity to it, I know I can use an H bridge for this, but I dont want to use an extra output on the controller just for turning stuff off with.
http://www.ebay.co.uk/itm/Solid-Sta...upplies_ET&hash=item27cad943b1#ht_1794wt_1398
The seller has this solution on thier ebay page :
I have built the came circuit on my breadboard, the theory I presume is that when the power is cut, the transistor discharges and flicks the switch back off again.
I haven't tried it directly with my picaxe yet, but only by hooking up my psu @ 5v to it directly, with the continuity tester on my multimeter on the switching pins of the relay. I turn on the power and the relay switches and the multimeter bleeps, I turn off the power and.......the multimeter continues to bleep. If I turn the power back on and flip the polarity nothing happens either as the capacitor stops the flow I presume. If I connect the backwards polarity to the relay directly it then clicks back, so I swap the leads once more and click it goes again, then stays on when the power is turned off...........
I have also put the multi meter on the capacitor and it is discharging / charging correctly, I have even tried a 100uf capacitor for a bit more grunt, but still nothing.
The only things I can think of is by turning off the psu or pulling the + lead that this is a different way to how the picaxe would turn the power off.....totally lost now.....
I have purchased off ebay some of these relays, they are really tiny an quiet, the problem is I didnt realise they were latching relays, so once the power is switched I cant get the damn thing to turn back off again without reversing the polarity to it, I know I can use an H bridge for this, but I dont want to use an extra output on the controller just for turning stuff off with.
http://www.ebay.co.uk/itm/Solid-Sta...upplies_ET&hash=item27cad943b1#ht_1794wt_1398
The seller has this solution on thier ebay page :
I have built the came circuit on my breadboard, the theory I presume is that when the power is cut, the transistor discharges and flicks the switch back off again.
I haven't tried it directly with my picaxe yet, but only by hooking up my psu @ 5v to it directly, with the continuity tester on my multimeter on the switching pins of the relay. I turn on the power and the relay switches and the multimeter bleeps, I turn off the power and.......the multimeter continues to bleep. If I turn the power back on and flip the polarity nothing happens either as the capacitor stops the flow I presume. If I connect the backwards polarity to the relay directly it then clicks back, so I swap the leads once more and click it goes again, then stays on when the power is turned off...........
I have also put the multi meter on the capacitor and it is discharging / charging correctly, I have even tried a 100uf capacitor for a bit more grunt, but still nothing.
The only things I can think of is by turning off the psu or pulling the + lead that this is a different way to how the picaxe would turn the power off.....totally lost now.....