ac POWER MONITOR

Posted on Feb 7, 2014

The 0-to 130-V voltmeter and neon `AC PWR` lamp provide an average indication of the ac power. The fuse and metal oxide varistor(MOV)protect the monitor against overvoltage spikes. Four 1N4004 diodes rectify the ac voltage, generating negative-going pulses twice per cycle(every 8. 33 ms for 60-Hz power). Variable-resistor F1 supplies a reduced ampl

Click here to download the full size of the above Circuit.

itude sample of these pulses to a missing pulse detector consisting of Q1, IC1, and associated circuitry. As long as the pulse amplitude exceeds the threshold value set by RI, IC1 continually triggers, keeping its output high. When the pulse amplitude drGps below the threshold value, IC1 times out with a time constant set by variable resistor R2 and the 0. 47- F capacitor. R2 is calibrated to read the number of cycles required for a dropout indication. It can be set between 1 cycle(about 17 ms)and 30 cycles(0. 5 second). When IC1 times out, its output goes low. This turns on LED1. The low output also triggers IC2, which is configured as a set-reset flip-flop. This turns on LED2. When the voltage returns to normal, IC1 again starts triggering and its output returns high, turning off LED1. LED2, however, remains on until the manual reset button is pressed. The circuit is powered by a 9-V battery and is assembled in a plastic or grounded metal case. No-tice that thqre`s no isolation between the ac power line and the monitor circuitry. Be careful to avoid electrical shock when testing the circuitry.

Leave Comment

characters left:

Related Circuits

Tesla Coils Wiring

Because of the high voltages found in a Charge & Primary sections it seems natural to look for cable with high voltage ratings, such as neon sign cable, medical X-ray equipment cable & car engine...

simple bus level-shift / I2C mosfet level converter Fairchild BSS138

While doing some background reading about the Philips I2C bus I came across an application note written by Herman Schutte (of Philips Semiconductors Systems Laboratory in Eindhoven). Mr. Schutte...

making a coolpix e990 dual USB / serial cable

How to make a combined / dual serial and USB cable for the Nikon Coolpix 990 (e990) camera.

PC/CP120 Digital Logic Design

A Dual Inline Package, or DIP switch can be used to select between 0 and 5 volts at some point in a circuit. Since the dip switch does not have any power or ground connectors this must be done...

Vehicle Sensor Control for Parking Lot Management System

As the title indicates the goal of the project was to develop a parking lot management system. In this project we had reduced our project into 5 design phases. In order to acheive the goal, we...

thermostat design

We are planning to use a Programmable Logic Device to control our seven-segment displays. This will be accomplished by using the 8 outputs from the Analog to Digital converter as the inputs to the...

The Cylonduino Arduino Experiement

I`ve been putting in a lot of extra hours at work the last week in anticipation of an editing deadline. Despite this, I thought it was about time that I attempt a little hardware hacking. Even...

measuring battery capacity with an arduino

I needed a couple of AA batteries and found the display at the supermarket where they were all arrayed. Normally when I`m shopping in the supermarket, I tend to look at the price/kg or price/l when...

New Circuits

Zero consumption Anti-theft High power Code Switch for E-Bike Batteries

This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
Ultrasonic distance finder circuit

The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Simple Metal detector circuit with CD4030

Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Fully automatic watering circuit for flower pots

Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
Simple deep searching metal detector circuit

The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
Sub-Harmonic Bass Converter for Electric Guitars

The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
Echo Depth Sounding Sonar for Boats

In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
100W HiFi Audio Amplifier Circuit

This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
Plant-Pot Water Level Indicator Circuit

A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....

Create NOW your QR MENU for your Restaurant / Hotel / Bar / Caffe,

Comprehensive ordering/paying features. fully personalized to suit your Business.

Update Anytime! Easy and Simple!

Popular Circuits

Class-A Power Amp

The capacitors needed for the power supply are massive to try to get rid of hum, and massive...

Multi-spark module for Electronic Ignition

Multi-spark ignition is very useful especially in the case of startings at low temperature and at...

Automatic lamp dimmer circuit

This automatic light dimmer circuit makes it possible to control a lighting system so that it...

12AX7/12BH7 Hammond Tube Preamp Project

Build a preamp that I want to use to take a 1/4" keyboard line level signal and drive a Leslie...

Self-powered Fast Battery-Tester

This circuit runs a fast battery test without the need of power supply or expensive moving-coil...

Mini efficient coil launcher from disposable camera flash

This is a fun and non-dangeros project for those people who like to throw projectiles...

TV audio circuit diagram TDA1521

Colour is often used as shown in audio circuit (TDA1521), the circuit is taken from Changhong...