Clarke 165 caps

[Hutcho]

I’ve got a really old Clarke 165 that I’ve managed to get going but the caps have seen better days - my question is anyone have any off these knocking about for some beer tokens or can I use a different type as in a single one - can anyone advise please

 

[Seadog]

Anything rated for high current use should do.
10,000μF 80v

 

[Hutcho]

Thanks seadog - would that be a single or three again ? I have got four 12000uf but rated at 63vdc

 

[Seadog]

3 off.
12,000 should be fine. 63v might be pushing it. If you can measure the peak voltage across them that will give you an idea if they're safe to use.
@eddie49 be able to help.

 

[eddie49]

I agree that 3 of the 12,000uF would do the job. If there is space and you can spare the 4th one, using all four of them will not hurt, the arc will be smoother. It is said that having a bank of multiple smaller capacitors is better than one large one - since they are in parallel, the "Effective Serial Resistance" ESR is reduced.
As for the voltage, 63v is perhaps a bit low. As Seadog said, measure the DC output voltage, with the welder "power" switch stepped up to the maximum. First with no capacitors at all, that will give you the Root Mean Square - rms - value. Then connect the 3 or 4 capacitors and check again. It will be the peak value, which should be 1.414 times the rms value. If this is close to 63v, then you ought to get caps with a higher voltage rating.

 

[Hutcho]

I agree that 3 of the 12,000uF would do the job. If there is space and you can spare the 4th one, using all four of them will not hurt, the arc will be smoother. It is said that having a bank of multiple smaller capacitors is better than one large one - since they are in parallel, the "Effective Serial Resistance" ESR is reduced.
As for the voltage, 63v is perhaps a bit low. As Seadog said, measure the DC output voltage, with the welder "power" switch stepped up to the maximum. First with no capacitors at all, that will give you the Root Mean Square - rms - value. Then connect the 3 or 4 capacitors and check again. It will be the peak value, which should be 1.414 times the rms value. If this is close to 63v, then you ought to get caps with a higher voltage rating.

Right brilliant thanks guys

 

[Hutcho]

So without at the min Iam getting 30v flat out
So now is it safe to connect the other four to see what I get ?
Thanks again guys

 

[Hutcho]

Ok but the bullet and connected them - hiding outside with the test pedal
And with the caps connected I get 43v
Only problem is I don’t think I can squeeze all 4 in so will it be ok with three ? Going to see if I can move things about and see but just incase it’s looking like three caps

 

[eddie49]

The rms value of 30v DC multiplied by 1.414 should make 42.4v, so your measured 43v is spot on.

The original capacitor layout was 3 x 10,000, making 30,000uF. You now will have 3 x 12,000, so the total capacity has gone up to 36,000uF. Since the tolerance of large electrolytic capacitors can be + or - 20 percent ( ! ), it is about the same as it was....

 

[Hutcho]

The rms value of 30v DC multiplied by 1.414 should make 42.4v, so your measured 43v is spot on.

The original capacitor layout was 3 x 10,000, making 30,000uF. You now will have 3 x 12,000, so the total capacity has gone up to 36,000uF. Since the tolerance of large electrolytic capacitors can be + or - 20 percent ( ! ), it is about the same as it was....

Brilliant - thanks guys , but if I can make the 4 fit as Iam thinking off mounting them under the top cover it will be ok Eddie ?

 

[Hutcho]

The rms value of 30v DC multiplied by 1.414 should make 42.4v, so your measured 43v is spot on.

The original capacitor layout was 3 x 10,000, making 30,000uF. You now will have 3 x 12,000, so the total capacity has gone up to 36,000uF. Since the tolerance of large electrolytic capacitors can be + or - 20 percent ( ! ), it is about the same as it was....

And I’ve learnt something new today - thanks

 

[Tom O]

I had a Millermatic 130 I picked up for $50.00 it would spew smoke when turned it on from 1 capacitor I replaced all 6 for I belive $300.00. The capacitors were a bit larger and was told it would be a little smoother.

 

[Hutcho]

They in - rough for now till cases are painted , going to use the bottom support to lift the wires up from rectifier out the way