# Safe voltage

1. May 28, 2010

### m718

Is 5000 volts at 1mA safe if accidentally touched, if so, up to how many mA is safe at this voltage?

2. May 28, 2010

### mgb_phys

We probably don't want to give safety advice to people in countries with lawyers.

1mA would probably be safe under most circumstances - the question is how are you limiting it to 1mA?
Is there any way a much more dangerous current to be passed if a component failed?

3. May 28, 2010

### Bob S

Be ABSOLUTELY sure that there is no stored energy (capacitance) anywhere. See Table 1 in attached

http://euverc.colostate.edu/safetytests/High_Voltage_Safety_Manual.pdf [Broken]

Just in case, put a 5 or 10 meg resistor in series.

Bob S

Last edited by a moderator: May 4, 2017
4. May 29, 2010

### m718

I will use voltage multiplier to get the high voltage, are the capacitors in the multiplier safe or are those the capacitance your talking about?

Last edited by a moderator: May 4, 2017
5. May 29, 2010

### vk6kro

Those capacitors, and especially the last one, would make the supply very risky and that is why Bob suggested putting some large resistance in series with the output.
Because even 1 watt resistors have maximum ratings of about 500 volts or less, you would need at least 10 of them in series to get some safety.

However, work on the principle that 5000 volts is NEVER safe unless you can prove that it is.
You won't get any second chances.

A small current may not kill you immediately, (or it might) but you can't tell what effects it has long term on your body.

6. May 29, 2010

### m718

What are the current levels in those shock you get by touching a car sometimes, it must be near 5000 volts or more and they are safe. Would it be safer if I used a transformer to step up the voltage?.

7. May 29, 2010

### mheslep

1-10-100 rule, which states that
http://www.ehow.com/how_5834615_avoid-electric-shock.html