Electronic controller for the solar pump

[hairybiker]

Being an ex-electronics engineer, I thought I would build a controller for the solar 12v pump.

Looking into circuits a simple PWM controller looked ideal.

Then I found this http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=160463785325 a 12V/8A LED controller. Now there is not much difference between the circuit needed to control LED's and small dc motors (like the pump) is negligible (a bi-polar transistor in the o/p circuit for the led and a FET in the motor) so I took the chance on this (for £4.28 delivered I figured I could use it for something else if it didn't work).

Well it arrived this morning, connected it up to my bench PSU and tested with some water in my MT. Control from full on to a dribble :thumb: Depends on the height of the pumping head of course (needs more power to push it up further) but a good amount for recycling mash run off at low setting.

Tested with a 12V switched PSU (plug top type like this http://www.dealextreme.com/details.dx/sku.15990) and it is fine with that as well

So worth a shot if you have one of these small pumps and want to control its speed. :drink:

 

[craigite]

I like that. It answers the questions that I've pondered for a wee while "what will I do if my trainset transformer dies?" :thumb:

 

[Muddydisco]

Also a £11 hornby power supply and speed controller works well

 

[hairybiker]

Also a £11 hornby power supply and speed controller works well

Pah! too llow tech

Anyway pwn is "better" for dc motors as it supplies the same voltage to the motor all the time, only the mark-space (on/off time) is changed, so you are not running it at 4V or 12V or WHY V. It is always at 12V.

 

[Muddydisco]

Yeah I just cheat :lol:

 

[Cussword]

I've got an old on/off switch off a christmas tree, & I change the voltage on the transformer to slow/speed things up

 

[hairybiker]

I've got an old on/off switch off a christmas tree, & I change the voltage on the transformer to slow/speed things up

That would be some mark/space ration about 3 sec on/off isn't it?