Wireless Voltage Tester

Description:

This is non-contact  voltage detector ckt it can be used to detect voltage without touching any wire or without removing its insulation it is easy simple and easy to make without any problem and this is tested circuit it contains following components

ic CD4060

LED

S1

R1=1KR

9VDC Battery

you may also like to read this:   Regulated Variable DC power Supply Unit

Working Principle:
Detection of voltage is not a big problem we can use a tester and check whether the voltage is available or not but tester is dangerous because it uses direct contact with live wire it may cause of electric shock but this non-contact voltage tester has a great advantage over an old testing method, when it is bring towards the service mains it will start working and its output can be checked by using a LED, when LED starts blinking that means you are near the voltage or current source you can use dual switching because in day timing it is difficult to see the blinking of LED due this day timing we can use a piezo Buzzer which sense the same output but now output is in sound form and easy to sense in day time.

Operation:

This non-contact voltage tester uses electromagnetic field to sense the flow of current or availability of voltage in mains and gives us output. We know that our mains may have 50Hz  or 60Hz frequency and this tester uses 3Hz frequency to detect the output.

The electromagnetic field from the mains power, which has frequency of 50HZ, to IC1, it is frequently divided out to Q4 that divided by 16, Frequency is equal 3HZ, and LED1 flashes to indicate that around the mains power. If there is no mains voltage or current to flow, there is no electromagnetic field. The output of IC1 is not up frequently 3HZ so LED1 does not blink.

Variable DC Power Supply Unit 1 - 30 VDC

Hi guys I am Waqar Ali and I am here to give you the exact information about regulated variable DC power supply unit. It is very simple and easy to make at home without any confusion. This Power Supply Unit contains different circuit parts each part has its own importance and usage. 

Transformer: a transformer is a device which is used to step up or step down the AC voltage here in our DC power supply we need upto 30VDC so first of all we need to use step down transformer which converts 220VAC into 18VAC .

Bridge circuit: A bridge circuit is nothing it is just combination of four diodes in particular manner to get two full wave rectifier outputs.

Filter circuit: A filter ckt is nothing it is just combination of capacitors in order to reduce AC component from DC power supply unit to generate pure DC voltage

Voltage Regulator : It is a three terminal IC which use to make DC output more smooth which is output of filter circuit and provide completely pure DC voltage .

Components

TR1= step down Transformer (220vac/18vac)

U1= LM317

D1-D4= 1N4007

D5= Red LED

C1= 2200uF (Electronlytic)

C2=100 nf  (ceramic disk capacitor)

C3= 1uF (electrolytic capacitor)

RV1= variable resistor 4.7K ohm
R1= 240 Ohm