JHolmes Posted September 26, 2014 Share Posted September 26, 2014 Friends, I have six 12V 5.5A water pumps I want to control and I think the ServoDog would be the best option.Is this correct? I see that two channels in the ServoDog can be configured to PWM channels but what I cannot tell is whether it will be able to handle 11 amps of power. Does my logic make any remote amount of sense? Jeff Link to comment Share on other sites More sharing options...
k6ccc Posted September 26, 2014 Share Posted September 26, 2014 No way! Without some buffering anyway. The two PWM channels can handle 2 amps each, and the digital outputs can do 24mA. I am assuming you are planning on on / off control and not trying to get variable control. What I would do is to have the digital outputs drive a darlington pair trainsistor (or create your own darlington pair with 2 separate transistors) and have that control the pumps. You need a total current gain of about 300 - hence the reason for a darlington pair. I would actually do it with 2 separate transistors using something like a 2N2222 driving a 2N3055. Of course you would need spike protection diodes so the turn-off does not kill the transistor from the inductive spike from the motors. If you need a schematic, I can draw one (I'm already doing this - although not for a water pump). Link to comment Share on other sites More sharing options...
JHolmes Posted September 28, 2014 Author Share Posted September 28, 2014 Actually variable control is EXACTLY what I need. At this point I'm thinking a CMB16 (or 24) connected to a series of H-Bridges that have PWM features.Can you recommend and H-bridge units or Dc-to-PWM boards? Preferably pre made (not kits). Link to comment Share on other sites More sharing options...
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