Pulsating DC voltage from rectifier D1 - D4 has a peak value 310 V This voltage is supplied to the spout of the power MOSFET T1 through a resistor divider R9. A control circuit ensures MOSFET will only deliver a short dive before and after the voltage through zero meshes. During this time do not go too far pulsating DC voltage 5 V. In a short time the same grading Capacitor C2 will be too fit, long time thereafter he gives the output current. Capacitor result should be worth a very large 10,000 μF. Load current pulses in a short time has a price peak in the 4th order A!
|Schematics MOSFET use BUZ74 and IC CA3130E|
Output voltage stability essentially depends on the load. Maximum output current can be 110 mA. Supply for control circuit is obtained from the resistor R2., Capacitor C1 and the diodes D5 and D6. Control circuit is formed penanding window of three op-amp. The correct calibration of the controlling circuit becomes very important. Before the nets are given, first set the P1 in the middle position and turn the S2 until penggesernya are on earth potential. Then connect the nets and inspect the working voltage range. Next connect a voltmeter (10V DC range) on the output and adjust P2 until the meter begins to deviate. Finally, set P1 for meter reading 4.8 - 5 V.
Use of this circuit is limited. Obviously, can not be used with equipment that must be electrically insulated by the nets. It is also equally good when used with equipment which is very sensitive to sigh and nails nets. But good enough for the equipment that is not enough place to net transformer. This unit should be used to power the equipment that was placed in a plastic container. Any equipment that is powered by this circuit should not be connected to other equipment via a cable. If required to do must be done through optical coupling only.
The amount of heat dissipation at T1 and R9 only around 3 W. So if this rangkian installed in small contacts, there would be no problem with the heat. During the assembly, carefully observe first-prevention precautions are necessary in connection with a circuit that works with the nets.
Warning! This circuit needs to be made with extreme caution, because the nets full voltage there at some point.