speed control switch

[ajs]

new switch and speed control switch replaced still no joy next : https://uk.farnell.com/united-automation/csr604a/ic-power-regulator-6a/dp/1213082 £27 odd i think ill sell it on but tell them about the problem we will see thanks for your help Mock

Under £17 inc VAT at CPC https://cpc.farnell.com/united-automation/csr604a/ic-power-regulator-6a/dp/SC11529 don't know why it didn't turn up on my earlier search. Buy a couple of screwdrivers or whatever and you'll be into free delivery although it's only a matter of £4 regardless.

Don't know why they're so much cheaper given they are a Farnell company but it often works that way for parts they stock.

 

[MorrisWoodman12]

The thing which strikes me is the size of the 'heatsink'. The data sheet seems to indicate 10degC/W minimum at a 1A load. There is no way 10degC/W is going to be achieved with that small lump of ally when it's not attached to something bigger. So is the problem because the 604A going into some form of thermal shutdown where at full speed less heat is generated though this is not mentioned in the data sheet. The data sheet does say that the heatsink should be unearthed though why the lack of an earth should cause this operation I have no idea.
Hope this helps.
Martin

 

[ajs]

Under £17 inc VAT at CPC https://cpc.farnell.com/united-automation/csr604a/ic-power-regulator-6a/dp/SC11529 don't know why it didn't turn up on my earlier search. Buy a couple of screwdrivers or whatever and you'll be into free delivery although it's only a matter of £4 regardless.

Don't know why they're so much cheaper given they are a Farnell company but it often works that way for parts they stock.

To follow up my own post I'd pick up some heat shrink to redo the insulation as well: https://cpc.farnell.com/pro-power/hs114-1-2m/heatshrink-3-1-3-2mm-blk-1-2m/dp/CB10000 for a whole 77p. Infinitely preferable to bodging the job with insulating tape. The stuff I quoted there is adhesive lined so I would test the controller first before you finally shrink it in place.

 

[mock]

speed control does not work on my diamond fret saw
Changed https://cpc.farnell.com/united-automation/csr604a/ic-power-regulator-6a/dp/SC11529
Changed https://cpc.farnell.com/bourns/93r1a-r22-a22l/potentiometer-linear-250kohm-10/dp/RE07611
Changed https://uk.farnell.com/united-automation/csr604a/ic-power-regulator-6a/dp/1213082
Changed https://cpc.farnell.com/multicomp-pro/mp1611/knob-25-4mm-w-dot-6mm-screw-black/dp/SW05902
next thing to change although the switch starts and stops as it should what's your thoughts

Toggle Switch, On-Off, SPST, Panel Mount, 10A -​

MCR13-5-05​

 

[scrimper]

speed control does not work on my diamond fret saw
Changed https://cpc.farnell.com/united-automation/csr604a/ic-power-regulator-6a/dp/SC11529
Changed https://cpc.farnell.com/bourns/93r1a-r22-a22l/potentiometer-linear-250kohm-10/dp/RE07611
Changed https://uk.farnell.com/united-automation/csr604a/ic-power-regulator-6a/dp/1213082
Changed https://cpc.farnell.com/multicomp-pro/mp1611/knob-25-4mm-w-dot-6mm-screw-black/dp/SW05902
next thing to change although the switch starts and stops as it should what's your thoughts

Toggle Switch, On-Off, SPST, Panel Mount, 10A -​

MCR13-5-05​

Does the motor run perfectly when connected directly? i.e. with the speed control bypassed.

 

[MorrisWoodman12]

I've just revisited this thread and have two comments.
@ajs suggested a particular speed control pot, one with a metal shaft. From a safety point of view this would not be recommended because the pot is connected to the incoming mains live. One with a non-conductive/plastic shaft would be mandatory. I can see you've already fitted the metal shafted one so please be very careful: you are only protected by the knob.
Take care
Martin

 

[MorrisWoodman12]

I notice in the excellent photos @ajs has posted there are three cables exiting the box. One is incoming mains and a second must be the motor: what is remaining one, the one on the right? Am I correct in assuming it's the little puffer motor thingy that blows the dust away?
I also notice the unit is not wired as per the data sheet. On the data sheet incoming live is connected to the controller pin 1 and via the pot to pin 1. Pin 3 goes to one side of the motor, the other side of which returns to mains neutral. On the data sheet incoming live goes directly to pin 2 and via the pot to pin 1. Pin 3 goes back to neutral via the motor. As the controller/pot combo and the motor are both series devices I can't see it makes much difference but who knows?
I agree with @Spectric and @Sideways that the earthing leaves a lot to be desired: there's not even a ring tag under the screwhead. I can't see the saw passing any form of regulation safely testing.