Australia's Science Forum

Hello everybody,

I was wondering what sort of power supplies you use for year 11 and 12 physics. We have just purchased some high power voltage 0-500V but now feel they are too high for the students to use. Have you done a RA for the use of your power supplies. Are there any special OH&S rules which state the max voltage that the students should be using.

thanks

Kerry

500V is pretty massive but look at the amps that are drawn at that voltage. 240V is mains - your voltage is approaching 3 phase! 240V is dangerous because it is very much in sync with heart pulses and therefore can be quite lethal - more so suprisingly than 3 phase.

Hi Kerry,

The 0-500V power supplies are not that often used in a high school environment. The main uses that I can think of is for running electrophoresis where a 100V DC voltage is required or to power a particular Teltron tube (cathode tube).

If you are after a pure (regulated) DC voltage, the high voltage supply maybe a little overkill.

Here, we mainly us the stock standard IEC lab power supply because it does not matter if the voltage is regulated or non-regulated for most of the work our Physics students. The output of those power supplies can be best described as crude (unsmoothed rectified AC).

For the more high end electronics work where pure DC is required, we have some regulated power supplies. These of cause are more expensive. And if you purchase from a scientific supplier, add another 20% (minimum) to the cost. You can look at Dick Smith Electronics or Electus (the wholesale division of Jaycar) where they have some regulated 0-30V DC power supplies for not that much more than the IEC lab power supply.

Cheers
Ross

Hi All,

Still do a Risk Assessment based on the type of power supply you have and keep these for Yr11 and Yr12 content only.

There may be uses for them in operating coils for Crookes tubes or CRO experiments (if your CRO has the support for 500V).

If you can vary the output which I seem to think you can then it allows for any changes where necessary. Also it give a power supply where it can run current through a wire with less chance of possibly tripping the power supply..

Inevitably the choice is yours.

Cheers,

Robb.....

Hi Kerry,

Usually a school would only have one of these "500 volt" power supplies as it would only be used on a demonstration practical.

I agree with the posts above, the IEC 0-12V or the 0-30V power supplies should be fine for lots of physics experiments.

How many did you buy? as they cost almost $500 each.

regards,
Goran