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110v to 12v power transformer - impossible to order
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<blockquote data-quote="fdlsys" data-source="post: 1130150" data-attributes="member: 2310"><p>12vac secondary voltage after the bridge, diode loss and capacitance is 16vdc. To drive a 5v DC motor? Regulator hopefully has a heatsink?</p><p></p><p>Heater element is a large power resistor (or a fuse if you are a pessimist). Resistors don't care about (typical household) voltage and they draw the amount of current that is inversely proportional to it's resistance. However, current draw (and amount of heat produced) is proportional to voltage so at 220v it will double that of 110v which will most likely cause the heater to act as a fuse.</p><p></p><p>Simplest solution: </p><p>220v/12(??) transformer for motor. </p><p>Incandescent bulb in series with AC supply for the heater. Bulb should have the same Watt power as the heater to act as a current limiter/voltage divider. Measure the resistance of the heater and calculate the power. In purely resistive AC circuit Ohm's law applies.</p></blockquote><p></p>
[QUOTE="fdlsys, post: 1130150, member: 2310"] 12vac secondary voltage after the bridge, diode loss and capacitance is 16vdc. To drive a 5v DC motor? Regulator hopefully has a heatsink? Heater element is a large power resistor (or a fuse if you are a pessimist). Resistors don't care about (typical household) voltage and they draw the amount of current that is inversely proportional to it's resistance. However, current draw (and amount of heat produced) is proportional to voltage so at 220v it will double that of 110v which will most likely cause the heater to act as a fuse. Simplest solution: 220v/12(??) transformer for motor. Incandescent bulb in series with AC supply for the heater. Bulb should have the same Watt power as the heater to act as a current limiter/voltage divider. Measure the resistance of the heater and calculate the power. In purely resistive AC circuit Ohm's law applies. [/QUOTE]
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110v to 12v power transformer - impossible to order
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