Hello all, trying to figure out why my cooling water seems to be at

Lasers
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1

Hello all, trying to figure out why my cooling water seems to be at the same voltage as a laser. Any thoughts?

2

use distilled water only, tap water can be conductive

3

Usually means that your coolant is to conductive. What voltage?

4

Yeah it’s a strange phenomena that happens when your cooling water becomes conductive. We aren’t completely sure why it happens. It can cause premature power supply failure as well. Change your cooling water to distilled water and don’t use any additives other than some algaecide if you need to.

5

@donkjr @Nedman I’m thinking this phenomena may have a use to let you know when it’s time to change your water. Say an approperate digital voltage display with a probe in the water flow and to earth ground maybe??

6

@Steve_Clark
I think a water conductivity tester is cheaper :).

I think that @HalfNormal has an arduino based one that could be a direct measurement approach.

…
The design problem may be that even at low current the voltage is high enough to fry an IC… I suspect the voltage is 100’s of volts.

Also we would have to find out empirically what are good and bad values.

A simple approach would be to try a voltage divider… with one of those cheap DVMs [which may need a battery]. Then again, you can get a DVM from HF for $10, or free on some holidays, stick it across the bucket to ground.

Here is a calculator: http://www.ohmslawcalculator.com/voltage-divider-calculator

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7

Bad water pumps can also cause “hot” water.

8

In still think a closed system may be better.

9

Thanks all for the help I’ll try distilled water next weekend.

10

What are you currently using?

11

Just tap water. Through the bucket was quite dirt, may have had something in it to add conductivity.

12

@Cody_Fitzgerald I have experienced tap water getting conductive as it ages.

If you have water conditioning that can also alter your waters conductivity. I have a NUVO system and that increases my conductivity.

Just say NO to all but distilled :)!

13

I agree with Don, distilled water only. I have a closed peltier system of only about two and a half liters and planned on changing it often. But it’s now at three months with no problems. However time to change anyway.