Rongge

The circuit consists of power supply and control sections. The power supply section is built around transformer X1, bridge rectifier BR1 and filter capacitor C1. The 50Hz, 230V AC mains is stepped down by transformer X1 to deliver a secondary output of 9V, 300 mA. The transformer output is rectified by the bridge rectifier and filtered by capacitor C1. Fan and Air-Conditioner Control Switch circuit Diagram When the mains is switched on for the first time, pin 3 of IC CD4017 (IC1) goes high and relay RL1 energises to switch on the fan. When mains is briefly switched off using S1 and then switched on, the power to IC1 is maintained by the charge on capacitor C1. At the same time, there is a trigger pulse on the clock input (pin 14) of IC1, which advances the decade counter and relay RL2 energises to switch-on the air-conditioner. Both the air-conditioner and the fan will be turned off if the switch is in the ‘off’ position. Assemble the circuit on a general-purpose PCB and enclose in a s...

This ultra-simple remote control extender is ideal for use with a hidden video recorder. The recorder is a Panasonic NV-SD200 and is used as part of a camera surveillance system. A PICAXE-08-based circuit is used to detect events and control the recorder. It also flashes a LED near the monitor to indicate the number of events since last viewing. Strangely, the NV-SD200 model refused to work with a number of commercial infrared remote control extenders, hence the need for this design. As a bonus, it uses less power than a traditional extender (no plugpacks) and the remote can still be used in the normal manner. As shown, an additional 5mm infrared LED is mounted directly in front of the equipment to be controlled. This is cabled back to a convenient location near the monitor and terminated in a 3.5mm plug. To modify the remote control unit, break the circuit to the anode of the existing infrared LED and wire in a 3.5mm headphone socket. In most cases, the LED will be accessible ...

Controlling temperature has been a prime objective in various applications including refrigerators, air conditioners, air coolers, heaters, industrial temperature conditioning and so on. Temperature controllers vary in their complexities and algorithms. Some of these use simple control techniques like simple on-off control while others use complex Proportional Integral Derivative (PID) or fuzzy logic algorithms. In this project Shawon Shahryiar discusses about a simple control algorithm and utilize it intelligently unlike analogue controllers. Here are the features of this controller: Audio-visual setup for setting temperature limits. Fault detection and evasive action. Temperature monitoring and display. Audio-visual warning. System status. Settable time frame. Data retention with internal EEPROM memory. [ ]

This circuit was originally designed for use in detecting discharges from individual neurons, where the infrequent discharges are difficult to separate from dominant background noise. It may also prove useful in other applications that need to detect infrequent low-level audio signals against a noisy background. The audio input signal is buffered by op amp IC1 before being applied to the opposing inputs of comparators IC4 & IC5. Positive and negative offset voltages are generated by VR1 and IC2 and fed to the other two inputs of the comparators. Essentially, the comparators act to produce a negative voltage at their commoned outputs (C) whenever the audio signal exceeds either the positive or negative offset voltage. Circuit diagram: Audio Level Threshold Control Circuit Diagram The signal at "C" is inverted by transistor Q1 to produce "D". These two signals are used to control a pair of CMOS switches (S1 & S2), which either pass the audio signal to the ...

Control cable length Q) How do I calculate the critical length on control cable for contactor? The permissible length of cable (m) can also be calculated by using the formula below: U : Rated coil voltage dU : Voltage drop ( 5%) Son : Coil VA / W at pick up Cos φon : p.f of coil at pick up R: Ohmic resistance/cable values as tabulated When long control cables are used for actuating the contactor, large voltage drop may occur causing chattering of the contactor or even failure to pick up. If the length of the cable exceeds L, use of higher size of cable or use of contactor relay is suggested as shown in fig. ..

See figure below its Control Relay Circuit Schematics.

Description  This is a simple type remote control by using RF communication without microcontroller. In this project a remote has been designed for various home appliances like television, fan, lights, etc. It gives lot of comfort to the user since we can operate it by staying at one place. We can control any of the appliances by using this remote within the range of 400 foots. In this project consist of two sections, transmitter (remote) and receiver section. Whenever we are pressing any key in the remote it generates the corresponding RF signals, and these signals are received by the receiver unit. ASK transmitter and receiver is used as transmitter and receiver. HT12E, HT12D encoders and decoders are used in this electronic circuit. The block digram of the whole circuit is given below.  Appliance Control Block Diagram Remote Section In remote section consist of an encoder (HT 12E) and a ASK transmitter. The encoder generates 8 bit address and 4bit data. We can set the addre...

Description: An Infra Red wired Repeater circuit to control appliances from a remote location. IR Remote Control Extender Circuit Diagram Parts List: R1: 1k Resistor (1) R2: 3.3k Resistor (1) R3: 10k Resistor (1) R4: 15k Resistor (1) R5: 2k2 Resistor (1) R6: 470R Resistor (1) R7: 47R Resistor (1) 0.5 Watt PR1: 4.7k Preset (1) C1,C3: 47u Elect(2) C2: 1n Polyester 5% or better (1) C4: 100u Elect(1) Z1: 5V1 Zener (1) Q1: BC549C or BC109C or 2N2222 (1) Q2: BC337 or BC549 or ZTX450 (1) IC1 : TSOP1738 IC2: 555 or 7555 (1) LED1 5mm RED (1) LED2,3 IR diode TIL38 or similar (2) Alternatives to IC1 : Everlight IR receiver module ELIRM 8621 Harrison electronics IR1 Vishay TSOP 1838 Radio Shack 276-0137 Sony SBX 1620-12 Sharp GP1U271R Notes: The signal emitted by an IR remote control contains two parts, the control pulses and a modulated carrier wave. The control pulses are used to modulate the carrier, a popular modulation frequency being 36 and 42KHz. The signal is radiated by an IR diode, ty...

3 Band Tone Control circuit uses an op-amp as an amplifier end. Tone Control circuit is a regulator of tone bass, midrange and treble or 3 band called because it can set the three tones. Filter circuit is applied to the series of "Tone Control 3 band" This type baxandal like the title of this article.  Results filtering regulator tone or tone control baxandal type is good, because there is no signal level is wasted directly into the ground. Range frequency tones generated from Tone Control 3 band was determined by the configuration of the R and C of the filter section baxandal. As an amplifier on Tone Control The set of three band use traditional IC LF351 has slewrate high and high input impedance. For more details, series 3 Band Tone Control as follows. Figure Series 3 Band Tone Control 3 Band Tone Control circuit above using LF351 Op-Amp is used to strengthen the signal after filtering by the filter process baxandal. Level tone Bass, Midrange and Treble settings are determi...