Inverter Oscillator Board using Flip Flops 74LS112

 

I’ve found this board in many inverters, and it works great with transistor type inverters. I have tested this kit with Mosfets, but the gate triggering was low, and had to be followed by some emitter follower network for proper operation.

This types of kits are very simple. Let’s check out it. This kit consists of main 3 IC’s. They are LM7805 +5V0 Regulator IC, that is used for digital signal passing.

Second one is a NE555 Ic, which is a widely used clock pulse generator. The third IC is 74LS112, which is dual -ve edge triggered JK flip flop. This changes state depending on clock pulses here. It is used to only toggle at -ve or falling edge as it’s all inputs (J1,J2,K1,K2) are set to logical 1 or high by a resistor to the +ve source.

The toggled output generates two opposite signals say Q and Q’ . They are then sent to a transistor (TTL) level amplifier to generate more strong signal.

The transistor network is made by 2 transistors each section, as C100(pnp) and BC548(npn). The overall output is then fed to the transistor power section of the inverter.

 

Pros.

1. High stable and frequency controllable oscillator kit
2. very cheap components and easy design
3. Can also work with MOSFETs with a little modification

Cons.

1. This is a square-wave oscillator, so inductive loads cannot run properly by this type of inverter
2. This being a squarewave oscillator, we cannot control PWM of it, and also can’t control power output by any input condition.

This kits are priced around 70-80 rupees only for good brand as ‘alfa’. Either buy a complete board, or make on vero, the item is as simple as it is.