12 replies to this topic

[WiredbyWilson]

has anyone attempted to convert thier single speed fan into a twin or more speed fan by fitting resistors etc like in modern cars?

obviously i could buy a twin speed but that is quite costly so am looking at other avenues.

any help/suggestions/i thinks are more than welcome.

[Big_Adam]

£50 is expensive?

Anyway, the thing about twin speed heaters being good is the bigger pipework. Not the twin speeds.

[SolarB]

Yep, you can modify an older heater to run two speeds as the normal single speed is a bit much most of the time. You need a 3.3 ohm 25 watt resistor and a new switch. The resistor is mounted inside the casing to keep it cool, the switch is a direct replacement for the original one. The 3.3 ohms resistor reduces the fan to a sensible slow speed. The next common value is a 4.7 but that runs the fan quite a bit faster. 25W is the minimum power resistor you can use but works as long as its firmly coupled to the fan casing.
[attachment=49497:DSCF2311_b.JPG]

And yes, £50 is a lot of money

Edited by SolarB, 04 February 2008 - 04:24 PM.

[Big_Adam]

Considering the twin speed go for £100-£150 it isn't.

That and I needed a heater.

[WiredbyWilson]

Yep, you can modify an older heater to run two speeds as the normal single speed is a bit much most of the time. You need a 3.3 ohm 25 watt resistor and a new switch. The resistor is mounted inside the casing to keep it cool, the switch is a direct replacement for the original one. The 3.3 ohms resistor reduces the fan to a sensible slow speed. The next common value is a 4.7 but that runs the fan quite a bit faster. 25W is the minimum power resistor you can use but works as long as its firmly coupled to the fan casing.
[attachment=49497:DSCF2311_b.JPG]

And yes, £50 is a lot of money

where can i get one of these fancy doo-hickys and a new switch, any help with the wiring dude

[HARBER07]

I once fitted a variable speed controller type of thing under the dash. It actually worked quite well and used the original switch just as an on off. Cost about £20.

[WiredbyWilson]

need more details guys, parts you used and how you wired it up pleeeeeeeeeeeeease

[SolarB]

Wilson1275. You need the following from Farnell electronics.

3.3 ohm 25 watt resistor 9507515 £1.62 + VAT. Qty. 1
Single pole double throw center off rocker switch 9562346 £1.04 + VAT. Qty 1.

Afraid I'm not placing an order with these people until next month but you should be able to find someone on TMF who can order them for you (you need a trade account).

[WiredbyWilson]

Wilson1275. You need the following from Farnell electronics.

3.3 ohm 25 watt resistor 9507515 £1.62 + VAT. Qty. 1
Single pole double throw center off rocker switch 9562346 £1.04 + VAT. Qty 1.

Afraid I'm not placing an order with these people until next month but you should be able to find someone on TMF who can order them for you (you need a trade account).

nice one, i will scout around the usual places like maplins and see if i can find them, alternatively my uncle is a motor trader so could set up an account for him lol.

Wilson

[HARBER07]

LINK
Costs £14.99 and i wired it in series after the switch so its not always live. And i just extended the cables from the switch. ie. i took the "live" to the switch, then from the switch to the controller, then from that back to the wire for the fan in the heater. Just need somewhere to mount it and if you have one of those things in the corner under the dash your laughing. (can also change the knob aswell).

Hope this helps.

[WiredbyWilson]

looks pretty funky, does the board get in the way at all??

has anyone got a trade account with Farnell and are feeling realy really charitable? *gets fiancee to flutter eyelashes cheekily*

[HARBER07]

I never had a problem with it getting in the way. Also came with a plastic spacer to space it off the surface so as to not short anything out.

[pickles]

A far better company "Rapid Electronics"
3.3ohm 25 watt power resistor 99p

Edited by pickles, 07 February 2008 - 10:24 PM.