A simple light / dark activated relay switch circuit, suitable for many applications like the automatic switching of the lights in a shop window or a room according to the ambient light level. The circuit uses a light dependent resistor (LDR). A light/dark option has been incorporated. The term 'light/dark' is used because the circuit has a PCB-mounted switch on board. In one switch position a light-to-dark transition will activate the relay. In the other position a dark-to-light transition is required. So you can use the falling light on the detector to switch on a normally off circuit or switch off a normally on circuit. The relay is on when LDR uncovered and relay off when LDR covered. Adjust VR1 for light sensitivity. LED will turn on at the same time with relay.
Posted on Thursday, May 12, 2011 • Category: Phone Circuits
This circuit detects the dial tone from a telephone line and decodes the keypad pressed on the remote telephone. The dial tone we heard when we pick up the phone set is call Dual Tone Multi-Frequency, DTMF in short. The name was given because the tone that we heard over the phone is actually make up of two distinct frequency tone, hence the name dual tone. The DTMF tone is a form of one way communication between the dialer and the telephone exchange.
A complete communication consist of the tone generator and the tone decoder. In this article, we are use the IC MT8870DE, the main component to decode the input dial tone to 5 digital output. These digital bits can be interface to a computer or microcontroller for further application eg. remote control, phone line transfer operation, LEDs, etc...
Posted on Thursday, May 12, 2011 • Category: Power Supplies
Simple, low cost and easy to build power supply. Ideal for applications that doesn’t require too much power. It can provide power to circuit that uses less than 100mA without any problem. The disadvantage of this circuit is the danger of an electrical shock, so it cannot be used if the circuit is in contact with the user. The voltage supplied by this is determined by the zener diode.
Posted on Wednesday, May 11, 2011 • Category: Amplifiers
I wanted to make this HI-FI Valve Amplifier so that MCS can be considered a classic brand like a lot, but my hand veteran tuner anfimden kopamıyordum transistor amplifier at the end of this one day I decided to take it in my hand as long as I have somehow amplifier kurtulamayacaktım air after breakfast and drinking my tea I gave trying to check if the decision is correct Cry with her almost 15 years we have not shared this with less than animism, but cherish her love of rock music by pressing the send us compelled to take this tube amplifier device bitirebilecektim yes, I was sure before I took a friend who wants to
3 months without music ... without it stood late Tagged with kamçılandım ITSELF HERE:)
Circuit-Zone.com © 2020. All Rights Reserved.