PWM DC Motor Controller

[Supertramp]

My 12v CH pump is very noisy, such that I couldnt sleep with it running.

(I have a near silent 240v standard domestic pump also inline for use with shore power)

 

Having already tried flexible mounts, rubber hose links etc, I have now thought of slowing the motor down.

 

12V-40V 10A Pulse Width Modulation PWM DC Motor Speed Control Switch Governor UK

http://www.ebay.co.uk/itm/121008731849

 

Would this work with a standard Jabesco pump? (59510-0012)

or could I cause more problems than I aim to solve?

 

Tony

[nicknorman]

My 12v CH pump is very noisy, such that I couldnt sleep with it running.

(I have a near silent 240v standard domestic pump also inline for use with shore power)

 

Having already tried flexible mounts, rubber hose links etc, I have now thought of slowing the motor down.

 

12V-40V 10A Pulse Width Modulation PWM DC Motor Speed Control Switch Governor UK

http://www.ebay.co.uk/itm/121008731849

 

Would this work with a standard Jabesco pump? (59510-0012)

or could I cause more problems than I aim to solve?

 

Tony

It's difficult to know if it would work because its a brushless DC motor. It would depend on the drive circuit. You might be able to get a clue by observing whether the pump speed changes when on batteries at 12.something volts, versus when charging the batteries at 14.something volts.

 

Alternatively you could try one of these small pumps from Solarproject which are very quiet and cheap and also do change speed with supply voltage.

 

Or you could ask Jabsco!

Edited February 26, 2013 by nicknorman

[Arthur Brown]

1/ Check with Jabsco

2/ try simply putting a 2 ohm resistor in series OK you will need a high wattage one (say 17w or more) just like car heater blowers used to do. Keep it cool and clear of heat sensitive things.

[Supertramp]

Thanks Nick & Arthur, some ideas there.

The solar project pump looks almost too good to be true for that money, have you any experience of them in actual use?

 

Arthur, - I was trying to save wasting the heat in a resistor, but I agree, - its a tried and test method.

[nicknorman]

The solar project pump looks almost too good to be true for that money, have you any experience of them in actual use?

Yes, I have one circulating my CH when heated from the engine via a plate heat exchanger. However, I have only installed it recently and it has only run for perhaps 20 hours so far (only on when engine running), but seems fine at the moment although obviously it is made a little cheaply and wouldn't stand much physical abuse. I took the view that if it packed up, I hadn't lost much! It is designed for continuous use with solar heating systems however, and the max flow maybe less than the Jabsco, but probably adequate for a moderately sized CH system.

 

ETA you can get the 11 ltrs/min version for another £3, which is close to the Jabsco's 12.5 l/min. The ports of the Solarproject pump are conveniently BSP threads so no rubber pipe with jubilee clips required, but the bore is quite small so I guess the 11 l/min ones have a pretty high fluid velocity which might create some gurgling noises!

Edited February 26, 2013 by nicknorman

[smileypete]

My 12v CH pump is very noisy, such that I couldnt sleep with it running.

(I have a near silent 240v standard domestic pump also inline for use with shore power)

 

Having already tried flexible mounts, rubber hose links etc, I have now thought of slowing the motor down.

 

12V-40V 10A Pulse Width Modulation PWM DC Motor Speed Control Switch Governor UK

http://www.ebay.co.uk/itm/121008731849

 

Would this work with a standard Jabesco pump? (59510-0012)

or could I cause more problems than I aim to solve?

Should do, PC cooling fans are often PWM controlled. Might be an issue with starting friction 'stiction' if it's set too low.

 

Other way is to use a DC-DC converter, maybe more reusable for other projects too :

 

http://www.ebay.co.uk/itm/310498700132

http://www.ebay.co.uk/itm/281069688273

 

Ideal setup could be a low temp thermostat on the back boiler that kicks in first giving the pump reduced power, then a high temp thermostat that gives the pump full power.

 

A cylinder thermostat (from £7ish on Ebay) can be strapped to the top backboiler outlet pipe, they usually have a changeover contact so you could switch between straight batt voltage or reduced power.

 

cheers, Pete

~smpt~

[Supertramp]

Yes, I have one circulating my CH when heated from the engine via a plate heat exchanger. However, I have only installed it recently and it has only run for perhaps 20 hours so far (only on when engine running), but seems fine at the moment although obviously it is made a little cheaply and wouldn't stand much physical abuse. I took the view that if it packed up, I hadn't lost much! It is designed for continuous use with solar heating systems however, and the max flow maybe less than the Jabsco, but probably adequate for a moderately sized CH system.

 

ETA you can get the 11 ltrs/min version for another £3, which is close to the Jabsco's 12.5 l/min. The ports of the Solarproject pump are conveniently BSP threads so no rubber pipe with jubilee clips required, but the bore is quite small so I guess the 11 l/min ones have a pretty high fluid velocity which might create some gurgling noises!

 

Thanks Nick, I've ordered the 6w one, as I don't want a high flow rate.

 

The DC-DC converter for high / low settings is also an idea I hadn't considered. - good to get other peoples views!

[nicknorman]

Thanks Nick, I've ordered the 6w one, as I don't want a high flow rate.

 

Let us know how you get on with it.