Ham radio power supply circuit with RFI elimination
Mini Projects
This is the Ham radio power supply circuit with RFI elimination for Amateur radio. A typically Radio transmitters use High-frequency transistors as current driver so can cause very severe electromagnetic. Therefore, The power supply must be able to make the current higher than 10A. Figure 1 the schematic diagram RFI elimination This circuit must have the RFI(Radio Frequency Interference) eliminate system or filter too much harmonic effect. More Ideas The output is 13.8 volts and has the short Circuit protection We want a circuit that is affordable, and easy to build. The use of the package IC number LM350T 3-Amp Adjustable …
Constant current circuit using LED
Power supply
This is Constant current circuit using LED. Normally the voltage drop across LED while forward bias will be about 1.2 to 1.4 volts depend on type of LED by has the temperature coefficient is -1.5 mV per degree Celsius. Which similar to the temperature coefficient of junction. between a base and emitter of silicon transistors. From this relationship can the constant current circuit that no temperature coefficient as show in Figure 1. Figure 1 Constant current circuit using LED From in the Figure current I flowing through the value. (U LED – U BE) / R And since temperature coefficient …
Super Steady Zener diode voltage regulator circuit
Power supply
This circuit is used for controls the voltage battery is steady, which the Zener diode voltage regulator circuit apply very low current about 1mA only, cause there is ripple voltage about 1 mV at voltage changing between 10 to 30 volts. As circuit the output is fixed to 8V. In circuit the reference voltage is connected to input of 741 OP-AMP (popular ICs) , to a non-inverting input and output of circuit will same the zener voltage multiply with OP-AMP gain as below. Vo = Vz * {(R2 + R3)/R3} The advantages of this circuit have two reasons. (1.) we …
Dual DC power supply rectifier using 2 terminal transformer
Power supply
There are many ways to build the Dual DC power supply rectifier from a transformer that has one secondary coil.This good way as Figure 1 use two bridge diodes. The first section is normally working, others section (D1-D4) will work by AC signal from C1 and C2. To filter DC voltage of out others bridge diode of transformer. It cause we can connect directly the positive of to the 0 volts. Thus, the output will be symmetric both positive and negative. And since C3 is charged by impedance higher than C4. Because value of C1 and C2. Thus value of …
5 volts DC Regulator Without Transformer Using MOSFET
Power supply
This is 5 volts DC Regulator power supply that without the transformer so small size, use the MOSFET is based. It is suitable the digital circuit. Caution! This circuit requires very careful to create. Because there is a high voltages many areas. The diodes D1 to D4 are used to convert AC power line to DC pulse voltage that have the peak is 310 volts. Then, apply to the drain of the MOSFET T1 by through the limit current resistor-R9. The controller circuit causes the MOSFET works briefly only, Before and after power cut at zero volts. In this time …