60W inverter using transistors

Here is the circuit diagram of a fully transistorized inverter that can drive up to 60W loads. Transistors Q1 and Q2 forms a 50Hz astable multivibrator. The output from the collector of Q2 is connected to the input of the Darlington pair formed by Q3 and Q4.Similarly the output of Q1 is coupled to the input of the pair Q5 and Q6. The output from the Darlington pairs drive the final output transistors Q7 and Q8 which are wired in the push pull configuration to drive the output transformer.
Circuit diagram.

60W inverter using transitors


  • The circuit can be assembled on a vero board.
  • T1 can be a 230V primary to 9-0-9V, 6A secondary transformer.
  • Transistors Q4, Q6, Q7 and Q8 must be fitted with heat sinks.
  • Use a 12V, 7Ah battery for powering the inverter.
  • Slight adjustments can be made on the value of R3 and R4 to get exact 50Hz output.