Diagram Guide

Monday, October 27, 2014

Switch Mode Power Supply

The purpose of these plans is normally straightforward, helped by the first-rate certification with the intention of is free. A average paradigm of a switch-mode power supply is that based on the LM2671 otherwise LM2674. The components intended for it are presented for outputs of 3.3 opposed to, 5 V and 12 V. near is and a version provided that a presettable output voltage. in the specified use, the materials can release currents of up to 500 mA. remark-worthy is the prohibitive switching frequency of 260 kHz.

Switch Mode Power Supply Circuit

pro with the aim of just low-appraise inductor and capacitors are required, and this results hip exceptional efficiency and unimportant dimensions. In typical circumstances, the efficiency is 90% and may perhaps even quit up to 96%. Both ICs provide protection in contradiction of current and heat overloads. The LM2671 has a add up to of other facilities such because soft start and the option to go to work with an outside grandfather clock. The latter enables several materials to happen in time so as to transfer better control of a few EMC (ElectroMagnetic Compatibility). The relevance publicized trendy the diagram provides an output voltage of 5 in oppositin to and an output current of up to 500 mA. Diode D1 is a Schottky type (Uco≥ 45 versus and Imax≥ 3 A).

Friday, September 19, 2014

Automatic TV Lighting Switch

The author is the happy owner of a television set with built-in Ambilight lighting in the living room. Unfortunately, the television set in the bedroom lacks this feature. To make up for this, the author attached a small lamp to the wall to provide background lighting, This makes watching television a good deal more enjoyable, but it ’s not the ideal solution. Although the TV set can be switched off with the remote control, you still have to get out of bed to switch off the lamp.

Circuit diagram :

Automatic TV Lighting Switch Circuit Diagram

Consequently, the author devised this automatic lighting switch that switches the background light on and off along with the T V set. The entire schema is fitted in series with the mains cable of the TV set, so there’s no need to tinker with the set. It works as follows: R1 senses the current drawn by the TV set. It has a maximum value of 50 mA in standby mode, rising to around 500 m A when the set is operating. The voltage across R1 is limited by D5 during negative half- cycles and by D1– D4 during positive half-cycles. T he voltage across these four diodes charges capacitor C1 via D6 during positive half-cycles. This voltage drives the internal LED of solid-state switch TRI1 via R2, which causes the internal triac to conduct and pass the mains voltage to the lamp. Diode D7 is not absolutely necessary, but it is recommended because the LED in the solid-state switch is not especially robust and cannot handle reverse polarisation. Fuse F1 protects the solid-state switch against overloads. T he value of use d here (10 Ω) for resistor R1 works nicely with an 82-cm (32 inch) LCD Lcd.

With smaller sets having lower power consumption, the value of R1 can be increased to 22 or 33 Ω, in which case you should use a 3-watt type. Avoid using an excessively high resistance, as otherwise TRI1 will switch on when the TV set is in standby mode. Some TV sets have a half-wave rectifier in the power supply, which places an unbalanced load on the AC power outlet. If the set only draws current on negative half-cycles, the cir-cuit won’t work properly. In countries with reversible AC power plugs you can correct the problem by simply reversing the plug. Compared with normal triacs, optically cou-pled solid-state relays have poor resistance to high switch-on currents (inrush currents).

For this reason, you should be careful with older-model TV sets with picture tubes (due to demagnetisation diagram). If the relay fails, it usually fails shorted, with the result that the TV background light remains on all the time. If you build this schema on a piece of perf-board, you must remove all the copper next to conductors and components carrying mains voltage. Use PCB terminal blocks with a spacing of 7.5 mm. This way the separation between the connections on the solder side will also be 3 mm. If you fit the entire arrangement as a Class II device, all parts of the schema at mains potential must have a separation of at least 6 mm from any metal enclosure or electrically conductive exterior parts that can be touched.

http://streampowers.blogspot.com/2012/06/automatic-tv-lighting-switch_11.html

Saturday, September 13, 2014

Build a Precision Narrow Band Tone Switch Wiring diagram Schematic

How to Build a Precision Narrow Band Tone Switch Circuit Diagram. This is a simple Precision Narrow Band Tone Switch Circuit Diagram. This signal tracker and lock detector combine to make a precision tone switch. Filter R3/R4/C2 determines signal capture and tracking range, as well as settling time. Max. VCO frequency: R& Min. VCO frequency: + Pin 9 voltage affects both.

Precision Narrow Band Tone Switch Circuit Diagram

The minimum at pin 9 is 0 V and the maximum at pin 9 is VDD. In the lock detector, the PC (phase comparator) outputs are pulses whose width is proportional to the phase difference between the two PC inputs. At lock up, the two PC outputs are almost mirror images. The output of IC1A remains low and IC1B is high. This lights LED1. If the loop is unlocked, the LED will not light.

Friday, August 29, 2014

Triac Light Switch as a dimers

The series of light switches this time slightly different from the voltage of work. The series of light switches can work directly on the AC power network. Light switches are using the main component of TRIAC and LDR. The circuit is very simple and the components were sold in the market.

If you want a light reception sensitivity of this circuit can be arranged then the 3.3 MOhm resistor can be replaced with a variable resistor. For more details can be seen from the following series of images.

Circuit Diagram

With Triac Light Switch series is as dimers, but dimers control performed by the reception of light around the LDR. The lower the intensity cayaha received LDR then bright lights. For installation LDR need to be considered so as not exposed to light from the lamp directly.

Low Voltage Remote Mains Switch

Low-Voltage Remote Mains Switch Circuit diagram. This schema allows a 240V mains appliance to be controlled remotely via low-voltage cabling and a pushbutton switch. The mains appliance (in this case, a light bulb) is switched with a suitably-rated relay. All of the electronics is housed in an ABS box located in proximity to the appliance. The pushbutton switch and plugpack are located remotely and can be wired up with 3-core alarm cable or similar. Cable lengths of 20m or more are feasible with this arrangement. When the switch (S1) is pressed, the input (pin 8) of IC1c is briefly pulled low via the 10mF capacitor, which is initially discharged.

Low-Voltage Remote Mains Switch Circuit diagram

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Low-Voltage Remote Mains Switch Circuit Diagram

The output (pin 10) immediately goes high and this is inverted and fed back to the second input (pin 9) via another gate in the quad NAND package (IC1d). In conjunction with the 1MW resistor and 470nF capacitor, IC1d eliminates the effects of contact "bounce" by ensuring that IC1c’s output remains high for a predetermined period. The output from IC1c drives the clock input of a 4013 D-type flip-flop (IC2). The flipflop is wired for a "toggle" function by virtue of the Q-bar connection back to the D input. A 2.2MW resistor and 100nF capacitor improve schema noise immunity. Each time the switch is pressed, the flipflop output (pin 13) toggles, switching the transistor (Q1) and relay on or off. Note that all mains wiring must be properly installed and completely insulated so that there is no possibility of it contacting the low-voltage side of the schema.