Homemade temporary power supply

1. Circuit Principle The transistor V, the N1 and N2 windings of the transformer T and the capacitor C form a transformer coupled LC oscillation circuit. Potentiometer RP and resistor R provide bias current for the oscillation tube. 2. Component selection: V uses 3DD59A, R uses a 1/4W ordinary resistor, C uses 0.22μF/50V, the transformer needs to be homemade, N1 and N2 windings use ?0.9mm enameled wire, N3 winding uses ?0.67mm enameled wire, the winding The frame can be made of 1mm thick cardboard. The magnetic core is preferably ferrite U-shaped or ring-shaped. If not, use ordinary E-type or F-type silicon steel sheets instead. Use a 6V battery for the DC current G. 3. Installation requirements As long as the components are in good condition and the installation is correct, it can be debugged. After powering on, adjusting RP can control the output power of the circuit. If the circuit does not vibrate, it may be a problem with the polarity of the feedback winding. Use the polarity identification method to identify it or reversely connect winding N1 or N2 and try again. The terminal with the "·" mark in the figure is the terminal with the same name. When the power grid fails, this circuit outputs alternating current with a frequency of 50Hz and a voltage of 220V±5% to ensure temporary power supply to electrical equipment.