David Forrest..

David, the time is rapidly approaching for me to wire up the air pump in the Dragonfish...out of the two boards you kindly sent me, which one will be favourite to run the little Koge air pump? Please tell me it will be the smaller of the two as things are getting very tight in the wtc!

If neither will do the job, do you have a circuit for a simple electronic, non reversible, on/off switch? The air pump can only handle a maximum of 4.8v, by the way.


Richard

Niether Richard,they will not work anywhere near 3volt, they really need around 12volt although I have run one at 9.4 and it seems ok.

A one word answer....naff!

How about this, then...Ripmax Xtra 12 one way esc, will work on eight cells, handles 12a, and it's a microscopic little thing, fits in the wtc much better.

Hi Richard,
Sorry but they "do what they say on the tin."
And the tin says 12v!

(What you have  are 12v H bridges which will give you reversible motor control at several amps. They are principally for water pumps and piston tanks where 12 volts is the norm. Please send them back if they are no good to you.)

To switch a 4.8 v motor just on and off is easier. The good news is that the PIC chip will give the output which can can then trigger a single transistor for on/off. The bad news is that I don't have anything off the shelf. Is there nothing commercially available to do the job? A r/c controlled switch?

David

PS I have just seen the post you have just added. That looks like the bad boy you want!

Thanks David, it was just a thought...I originally was going to use one in the Skipjack and the other in the X craft, both using water pump systems, so I think I'll stick to Plan A.

I'll use the "bad boy" for the Dragonfish....(bad boy? you're getting very cool, dude...)



Richard

That sounds like a good plan, Richard.

Sorry about the "bad boy" stuff - that Jamie and his recipes! (I am a "Hep Cat" at heart.)

David

A "Hep Cat" eh? Good grief, you get worse!

(far out, man...)

Richard, ripmax extra 12 wont work at the voltage you are looking for,use the board out of an old servo as a 4.8 volt speed controller,take the board out remove servo motor, then connect servo motor leads to pump,take the red and black leads out of servo plug and run the back to the stand alone bec output side (4.8 volt) this take the load of the rx rail,plug the remaining white signal lead in to rx as normal, centre the pot on the servo board and jobs done it will now work as a two way speedo,if you only want one way trim the pot on the board and that should do it,or of course you could operate the valve of one side if you need to.