Transistor Dc Converter | Electronic Project Circuits

Posts Tagged ‘transistor dc converter’

Transistor regulator circuit can adjustable output voltage

This circuit is maintain a constant voltage, the output voltage is adjustable.Serves to reduce the input voltage, and keep the voltage constant.
The Q1 2N3904 is the amplifier model. common-emitter. This causes the voltage across the collector’s pin with the ground.Is equal to the voltage between the legs to the ground base of Q1. The volt base-emitter (0.6 V), the zener diode volt (6.2 V), then adjust the voltage VR1.
This circuit has a temperature coefficient is very little, almost zero. The joint base – emitter of Q1 with a temperature coefficient of -2 mV per Degree Celsius And zener didoe ZD1 have the temperature coefficient of +2 mV per degree Celsius. Reduce the effect of temperature on the circuit.
The Q2 to drive the output up. However, the output voltage drops, which can be adjusted with VR1 voltage range 6.8 – 15.6V. The R3 and C1 act as RC filters, voltage ripple less.But this circuit is less than 100 mA current only, is ideal for low current circuits.

Be the first to comment - What do you think? Posted by admin - July 23, 2011 at 6:52 pm

Categories: Power supply Tags: 2N3904, constant voltage control, transistor dc converter

DC converter 6V to 12V by BD679

This circuit is power supply circuit, again the circuit that have the merit is if we want dc voltage 12V but , we have 6 volt only the circuit can modify DC voltage 6 Volt be 12VDC get.

The principle works of the circuit is Q1, Q2, R1, R2, R3, R4, R5, D1, C1 and C2 build the circuit is model astable multi vibrator give output be Square Wave. Which be positive pulse signal at have many frequency. And have R6 perform be limit current already flow come to reach at a pin B of Q3 and a pin C of Q4 in this condition current at flow come in pin way B of Q3 make Q3 bias. But Q4 still not bias. Because of still have no current bias at a pin B. When Q3 bias make have current flow through L1, D2 change ZD1 cause drop voltage at ZD1.

Which be output voltage and voltage this increase continually poverty voltage that equal to 12 the volt. By have R7 be limit current already change come in the way pin B of Q4 make Q4 work be make Q3 stop bias. Then make output voltage be 0 volt, but when positive pulse signal that made come to then change come to at R6 then make Q3 bias again. And work character as before but there are many speeds then can make output that appear can come out 12 volt all the time by have C3 perform in something current filter smoothly before increasingly lead output voltage go to be usable.

Be the first to comment - What do you think? Posted by admin - June 26, 2010 at 5:37 am

Categories: DC converter Tags: 6V to 12V, step up dc converters, transistor dc converter

2W Switching Power Supply with 2N3053

In this small switching power supply, a Schmitt trigger oscillator is used to drive a switching transistor that supplies current to a small inductor. Energy is stored in the inductor while the transistor is on, and released into the load circuit when the transistor switches off. The output voltage is dependent on the load resistance and is limited by a zener diode that stops the oscillator when the voltage reaches about 14 volts. Higher or lower voltages can be obtained by adjusting the voltage divider that feeds the zener diode. The efficiency is about 80% using a high Q inductor.

Read More Source:http://www.uashem.com/pageid-447.html
Thank you.