Dummy loads (was: Re: new here)

A book entitled 'small AC transformers' [1] gives the following instructions for making chemical rectifiers. "The satisfactory operation of this type of rectifier largely depends on the condiiton of the electrolyte., and in its preparation the following directions should be attended to. Make a saturated solution of commercial phospate of ammonia in warm water , stiring thoroughly until disolved, and when cold test with a slip of blue litmus paper. Probably it will be found to be strongly acid and the paper will turn red. Drop in a little liquid ammonia, stirring well until the precipuiate it forms is again disolved, and take another litmus test. When the paper ceases to redden the acid will bave been neutralised and the solution ready for use. Fill each jar two-thirds full and then float half an inch of paraffin oil on top of the solution. This prevents evaporation and creepage of the salds. In course fo time the soltion will become acid again and then requires neutralising with ammonia as before. Set up in this way the chemical rectifier will give exceedingly good service; without these precaustions it is a messy appliance and likely to earn a bad name for itself. Keep it as cool as possible since the rectifying action falls off as the temperature rises' That's for a rectifier with aluminium and lead electrodes, BTW [1] YEs, I know all staticve transformers only work on AC. At the time this book was written, the term 'DC transformer' was used for a motor-generator set. -tony