Uc3843 Switching Power Supply Schematic

This circuit is based on a uc3843 integrated circuit.

Uc3843 switching power supply schematic.

The schematic in my db of reverse engineered schematics. During the q1 performance the current is passed through c8 c9 l1 and q1 when q1 stop or open circuit energy stored in l1 will evolve through d2 and c8 c9 in the same direction makes the output voltage is constant on all times. Http danyk cz reverz44 en html today i made a teardown of an industrial switching power supply mod. The feasible power output is approximately 120w.

The core of the switching transformer can be found in crt television or crt. The uc3843 can be used to regulate or limit current in application like smps rps dc dc converters line voltage regulators etc. You will use it outside the limits of the power supply. Do not use it outside the limits of the power supply.

So if you are looking for an ic to produce pwm signals for controlling a power switch based on the current flowing through the circuit then this ic might be the right choice for you. Both q1 and d2 will be passed to a high current this will work alternately. On pin number 2. The maximum total load is about 60w.

The output voltage is totally determined by the turns ratio in transformer t1. The uc3842 and uc3843 are used for voltage regulation. This switching power supply operates in the wide range of nominal input voltages 100 240 vac and is short circuit proof. This is a somewhat experimental circuit and i especially designed this circuit for those persons that want to dabble in switching power supply designs.

How o use uc3843 ic. Vcc 6 5 v for ucx843a vcc 14 v for ucx842a operating icc 0 5 12 1 0 17 0 5 12 1 0 17 ma power supply zener voltage icc 25 ma vz 30 36 30 36 v 4. Starting of this supply is ensured by the 220k 2w resistor. It does not allow for feedback control of the output voltage.

Figure 1 the basic of dc switching power supply. This winding is also used to power the uc3842. Adjust vcc above the startup threshold before setting to 15 v. In order to simplify the connection reduce the number of components and reduce the expected sources of problems the following sections have been omitted around the uc3843 circuit.

12v smps adapter can be used to charge 12v battery by setting 14 2v but using too much voltage for 6v battery will cause malfunction. The transformer will be used for this purpose. Dn 26 uc3842a low cost start up and fault protection circuit. Power supply current note 4 startup.

Dn 27 uc1842 uc1842a family summary of functional differences.