RE: Transformer

24 VAC 10 Amp Transformers are shown in a catalog called Marlin P. Jones & Assoc. Inc.
http://www.mpja.com The 24 VAC Transformer is $17.99 with part number 7846-TR
It is center tapped (12V - 0V - 12V) and this will, of corse allow for unregulated power supply construction of 12 VDC employing the center tap, or 24 VDC using a full wave bridge rectifier. Because 24 VAC is R.M.S. Voltage, as you know, the unregulated DC voltage is aproximately 1.41 times higher (1.41 X 24.0 = 33.9 VDC) Always practice Safe Power Supply All pun's aside, it gets a little deep in computational exercise with low line (plus) temperature rise (plus) regulation (plus) 50 HZ operation (plus) Filter cap size and so on. With large transformers, the one topic not disscussed a great deal is Temperature Rise. When a transformer is operated even with a poer factor of 1 (resistive load), because it is not 100% efficient, a portion of the energy will be generated as heat in the transformer. This gets worse as the power factor shifts because of the capacitive or inductive loads. A 24 VAC 10 Amps transformer will generate some heat. It is a good idea to include a fan in your box to remove the heat.

Marlin P. Jones also offers some regulated power supplies which are worth a note here. Example:
+5 VDC 1.5 Amps with -5 VDC 0.5 Amps (Linear regulated supply) 11540-PS $6.95

David R. Howland dhowland@...