Published:2011/7/19 9:46:00 Author:Nancy | Keyword: Adjustable regulated power supply, overload, short circuit protection | From:SeekIC
The circuit has the overload, short circuit protection and alarm function. Under the overload condition, the voltage drop of the resistor R8 increases. When the voltage drop reaches 0.6V, SCR conducts, which makes the Q1 base electric potential drop to about 1V, so the transistor Q1 and the regulating transistor Q2, Q3 cut off to protect regulating transistor from burning out. After Q2 and Q3 cut off, the output voltage is zero and the electronic switch Q4 cut off, Q5 conducts, which make the multivibrator composed by Q6 and Q7 start oscillation (dozens of Hertz), light-emitting diode LED2 flashes to alarm.
Reprinted Url Of This Article:
http://www.seekic.com/circuit_diagram/Power_Supply_Circuit/Adjustable_regulated_power_supply_circuit_with_overload_and__short_circuit_protection_function.html
Print this Page | Comments | Reading(3)
Code: