Building a titanium anodizer power supply, variable 150V DC max, variable 0-5A, circuit needed

Thread Starter

Chris Botha

Joined May 7, 2020
2
Can anyone maybe point me to a source for a circuit that will supply what the title states. Working of 240V mains. This will be used to anodize titanium parts for folding knives as well as for carbidizing the face of the lock lever.
 

Hymie

Joined Mar 30, 2018
819
I would think the cheapest solution would be to use a 750VA (or 1000VA) isolation transformer (not auto-transformer) with a rated input of 240V output 120V, and the input voltage driven from a variac to adjust the voltage from 0 – 270V. The transformer secondary output would be fed into an adequately rated (voltage and current) bridge rectifier. There should be no need for capacitive smoothing of the secondary d.c. output since the function is a plating application (works with raw d.c.).

The above parts could be purchased for less than £200, which compares favourably with the ebay unit below.

You might like to add output voltage and current meters, plus over current protection (fuses) at appropriate circuit locations.

https://www.ebay.co.uk/itm/1-x-EA-PS-3150-04B-Digital-Bench-Power-Supply-0-150V-dc-0-4A-640W/223015790913?hash=item33ecc6e941:g:U0IAAOSwz35bIAmY
 

Thread Starter

Chris Botha

Joined May 7, 2020
2
I would think the cheapest solution would be to use a 750VA (or 1000VA) isolation transformer (not auto-transformer) with a rated input of 240V output 120V, and the input voltage driven from a variac to adjust the voltage from 0 – 270V. The transformer secondary output would be fed into an adequately rated (voltage and current) bridge rectifier. There should be no need for capacitive smoothing of the secondary d.c. output since the function is a plating application (works with raw d.c.).

The above parts could be purchased for less than £200, which compares favourably with the ebay unit below.

You might like to add output voltage and current meters, plus over current protection (fuses) at appropriate circuit locations.

https://www.ebay.co.uk/itm/1-x-EA-PS-3150-04B-Digital-Bench-Power-Supply-0-150V-dc-0-4A-640W/223015790913?hash=item33ecc6e941:g:U0IAAOSwz35bIAmY
When I started researching the solution for this, an isolation transformer was the first thing that came to mind. Locally they tend to be rather hard to find second hand, and new they tend to be on the expensive side. If one compares the cost of a power supply that will supply the needed voltage and current, it might be similar if not more expensive, of which the transformer represents a large portion. If i might be able to source something second hand that will supply me with the required 200 V ac input, all I need then is the circuit to rectify (simple enough) and then voltage and current control. Anyone have something like this available?
 

jpanhalt

Joined Jan 18, 2008
9,426
Have you considered a constant voltage transformer (ferroresonant)? They provide stabilized voltage for reproducibility and isolation for safety. I got a used one for a reasonable price off eBay awhile back. No problems with it.

Some links of interest:
https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2334524.m570.l1313.TR2.TRC0.A0.H0.XSola+transformer.TRS1&_nkw=Sola+transformer&_sacat=0&LH_TitleDesc=0&_odkw=solar+transformer&_osacat=0

https://solahevidutysales.com/cvs_hardwired_series_power_conditioner.htm
 

Hymie

Joined Mar 30, 2018
819
It is possible to make such a circuit minus the isolation transformer – using just a variac and bridge rectifier. But the whole circuit would be considered live, and no part of the energised circuit could be accessible. This would include any part of the plating solution and the conductive parts of the bath/container. You should only consider this option if you have a controlled area where access is prohibited to persons who are not aware of the electric shock risk of the plating rig and adequate safeguards are in place (barriers/warnings/interlocks etc).
 
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