Petrol pump overall

Post by **millerman** » Thu May 13, 2004 12:02 am

Have just spent 2 hours tryig to get a petrol pump to work to use as a spare. Have followed the Haynes manual especially screwing in the operating rod from the diaphragm to get the correct throw. When connected to a battery charger it dosen't work!
Should I connect to the battery to get a better current to test?
Any advice most appreciated

Post by **rayofleamington** » Thu May 13, 2004 10:57 am

they will (normally) run off a battery charger, but if it's a bit sticky, maybe that's not helping. If it's playing up - it might be a good idea to use a fuse when connecting to the battery!
(although I often ignore that and use jump leads to check out if something works or not

- it's a very bad idea !!)

I had problems when installing new points in a pump (new points but many years old) - the points had a skin and therefore the pump didn't work until I cleaned up the surface of the points with emery.

Post by **millerman** » Thu May 13, 2004 10:06 pm

Have checked using the battery and the pump ticked away merrily! have now got a spare to carry.

Post by **Willie** » Sun May 16, 2004 6:46 pm

It appears that you have a very feeble battery charger!!

Post by **rayofleamington** » Sun May 16, 2004 6:53 pm

A battery has a big capacitance, and is able to deliver a big current spike if/when required - a charger will have a much lower peak current capacity. Now that your pump is chugging (freed up) it may well work on the charger.

Post by **newagetraveller** » Sat May 22, 2004 10:15 pm

A battery has a constant DC voltage output.
The output from a battery charger is full-wave rectified AC

Post by **Matt** » Sat May 22, 2004 10:17 pm

but if it is recitified using capacitors it can be got pretty close to plain DC

Post by **newagetraveller** » Sat May 22, 2004 10:27 pm

That is true.
But I have never come across a battery charger with a smoothing capacitor in it.

Post by **Matt** » Sat May 22, 2004 10:29 pm

Ive never looked...........

Post by **Cam** » Sun May 23, 2004 5:41 pm

Car battery chargers produce a VERY lumpy output full of nasty harmonics which is fine for battery charging but no use for powering audio/radio equipment. They don't have smoothing capacitors fitted as they are not needed for battery charging.