Simplex 478-353 — 220 VAC mains power transformer for Simplex 4100 series power supplies and the 100 watt amplifier.
The power supply modules in a 4100 system step incoming mains down to the low voltage rails that run the panel, charge the standby batteries and feed the notification circuits. This transformer performs that step-down, and the 220 VAC figure is its primary input, not an output. Simplex catalogues it as the service part shared by the System Power Supply (SPS), Expansion Power Supply (XPS), Remote Power Supply (RPS), TrueAlert Power Supply (TPS) and the 100 watt amplifier.
- 220 VAC primary; mains transformer, not an audio transformer
- Serves the SPS, XPS, RPS and TPS power supply modules
- Also used with the 100 watt amplifier
- Listed in the 4100U and 4100ES service parts lists
- Counterpart of the 120 VAC transformer 478-352
The part most easily mistaken for it is 478-352, the same transformer wound for 120 VAC. Distinct again are the amplifier audio output transformers beside it: 478-369 is the 25 V unit for the 100 watt amplifier and 478-370 the 70 V one, replacing 478-363.
