Re: [DIYbio] A simple and cheap >100V DIY electrophoresis power supply

Current limiting is more for fire prevention than human safety in my
suggestion. The power supply is basically boiling the buffer slowly.
As it heats up the buffer, the resistance of the gel decreases as it
melts, which increases the current, and so on - until the gel becomes
solution again and resistance is so low that current overloads the
bridge and the bridge starts to smoke. If the bridge burns into a short
or etc, then things will get hot really fast. Then the duct tape will
catch on fire and the case if any will melt. And so on.. This could
all happen without the main's circuit breaker tripping (@ 15A or @
30A). Even GFCI would not be protection in this case.

## Jonathan Cline
## jcline@ieee.org
## Mobile: +1-805-617-0223
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On 7/4/13 5:36 PM, Alexey Zaytsev wrote:
> 1) Fuses don't change anything here, they are to protect your wiring,
> not yourself.
> 2) Current limit makes no sense regarding safety here. The current
> that runs through the gel is much higher than the current that would
> ever run through a person who's grabbed the electrodes,

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