Current limiting for around 10 amps at 12 volts for electrolysis cell?

I am running an electrolysis cell off a modified ATX computer power supply. If I run the cell of 12 volts it will draw around 20 amps which is more than the power supply can handle and causes it to shut down after a few seconds. If I run the cell off the 5 volt port it only runs at around 2 amps, well below what I was hoping to get the cell to run at.

Does anyone have suggestions to limit the power to around 100 watts (8-10 amps at 12 volts)?

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lemonie7 years ago
Reduce the ionic strength of the electrolyte, i.e. put less salt (or whatever you're using) in the water.

Seconded, simplest solution.
danlab (author) 7 years ago
Problem solved, I messed up on some of my calculations and ended up with about 3 times the electrolyte I intended. After fixing that the cell still ran at too high of current so I went to about 20 grams of electrolyte per 500ml of water (I started with about 200 grams/ 500ml oops) and the cell is running about 50 watts,  less than I would like but I would rather take longer to produce what I need than burn up another power supply.
framistan7 years ago
Connect a regular LIGHT BULB in series with it.  That will limit the current to the value of the bulb... and BONUS gives you a visable indication that current is flowing. 
seandogue7 years ago
build a 10 amp variable current regulator so you can control the rate of electrolysis.
You can change the resistance presented to the power supply, adding a 0.6 Ohm resistor in series with the load, which you say looks like 12V/20A or 0.6 Ohms - you'll get 6V across it and the load, and it will carry 10A, but you can't get 100 Watts into your load, only 60W