Sunday, August 9, 2009

Table Lamp Circuit by IC 555

If you want a Power Lamp Flasher at normal electric power, try out Table Lamp Circuit like this is. It uses the integrated circuit NE555 as the core component. It controls the blink rate of the lamp. Use the power transistor for about 20W or current 1.6A. The Q3 can be replaced by TIP41 or H1061 or MJ3055 or 2N3055 .

Sunday, May 3, 2009

Inverter DC to AC

Sometime we go to camping, fishing and make some out door activity that need electricity, then we can overcome this problem by using gasoline or diesel generator sets. It is all right if we can handle this equipment. But if its weight is a problem too, then we need light AC power supply. A light AC power supply is realized by DC to AC inverter.

Basically, DC to AC inverter work by using control circuit to generate electric pulse at high power (typically at hundred to thousand watts) and then this high power pulse is connected to step up transformer to get high voltage, i.e. 220 volt. For example, this control circuit can be realized using microcontroller circuit as seen at figure1. By using a microcontroller, the generated pulse can be formed in modified sine wave by using pulse width modulation technique. We can built simple inverter using unstable multivibrator as be explained in simple inverter's page.

In this circuit, AT89C2051 (belong to AT89 series) is used to generate pulse that is used for MOSFET IRFZ 44 driving. This mosfet switched on and off DC current to low side voltage transformer. The high voltage is generated at the other side that can turn on the lamp. To get a higher power, we can add more mosfet in parallel connection.