I have a 120v X 24v step down transformer that is capable of supplying 30 amperes. I need to convert the output to dc to supply a project I am working on. I have a bridge rectifier capable of handling 10 amps continuously, but nothing that could handle the 30 amp output. What would occur if I put the rectifier on the input side (with no filter capacitors) and fed the xfmr the DC voltage with 120hz ripple? I suspect the xfmr wont like the 120hz input and generate excessive heat. Anybody know for sure? The xfmr has a laminated iron core and copper windings.
You are asking some strange questions. You do not have a very good understanding of transformers. A transformer ONLY works with AC. This is why Tesla argued for AC being supplied to houses. With a simple transformer, the voltage could be increased for less loss on transmission lines and then with a step down transformer, the AC could be brought into homes. Edison, on the other hand, loved DC and wanted all houses to be supplied with DC. Edison, in an attempt to prove Tesla wrong, invented the electric chair to show how dangerous the larger voltages would be. Edison even electrocuted animals in his electric chair to demonstrate the effects of higher voltages. Fortunately, Tesla won the argument, or we would not be able to transmit electricity over high power lines from generators to homes. Now, a rectifier in the strict sense, does not change AC to DC (with ripple) but simply reflects the negative wave to make it positive. Thus adding a DC component and doubling the frequency. The DC component will simply pass through the transformer (no heating) and the higher frequency will work just great with the transformer. In fact, you can make smaller transformers by using higher frequencies. This was a technique that Sony used many years ago to make great amplifiers and Fisher and Paykel use to make better appliances. (Other companies might also, but I am not aware of them.) So, your transformer will only see an input of 60 V AC and step that down to 12 V. Thus, you will not have the 24 v you need. Why don't you get a better bridge??
The transformer will not work correctly with pulsating DC. It will overheat.
