Inverter 100W by IC 4047 + 2N3055 (with PCB)

Inverter 12V to 220V 100W by Transistor

This circuit power Inverter 100W, it easy and good ideas. If you want to use some devices in your vehicle that needs AC power, you can use this circuit.

Computerize Your Room/House

This is about the most basic interface you will see. It uses only 3 74376's (74LS367). This interface provides 8 outputs (plus 3 address lines) and 5 inputs. This is usually enough for one room, providing you make use of some demultiplexers and the address lines. You could have up to 128 output lines using the address lines, a 74LS138 and 8 74LS154's.

Computer Controlled Frequency Counter/Logic Probe

This circuit is a stable frequency counter accurate to 5 significant digits. The range is 0 - 30MHz with an input sensitivity of greater then 100mV. The probe connects to the PC serial port. So by using the crystal oscillator already present on your PC serial card and software calibration, the Probes' external circuitry is kept to a minimum. Probe 9 can also be used as a logic probe/analyzer using included software (LPROBE92.EXE).