Matt circuit

The SMPS described here is suit-able for high-wattage stereos and other similar equipment. The circuit employs two high-voltage power transistors (BU208D) which have built-in re-verse-connected di-odes across their collectors and emitters. It can supply about 250-watt out-put. The circuit uses a ferrite core transformer of 14mm width, 20mm height, and 42mm length of E-E cores. An air gap of 0.5 mm is required between E-E junction. Good insulation using plastic-insulating sheets (Mylar) is to be maintained between each layer of winding.  Switch Mode Power Supply Circuit Diagram The number of primary turns required is 90 with 26 SWG wire. The secondary winding employs 17 SWG wire (for 4A load current). Each turn of the secondary develops approximately 2 volts. The reader can decide about the output volt-age and the corresponding secondary turns, which would work out to be half the desired secondary voltage. The volt-age rating of capacitors C7 and C8 should be at least twice the seco...

In recent years, the use of switch mode power supply (SMPS) has become more comon as more applications demand for greater power eficiency. It makes use of semiconductor (mostly MOSFET) fast switches to switch DC input that has been rectified at high frequency. The advantages of high frequency switching are that it reduces the size of inductor, capacitors & transformer used. Other advantages of switching power supply over linear power supply are : 1) High Efficiency (up to 90% and above for nice design). 2) Output can be higher than input. 3) Able to operate over a variety of input power supply. 4) Able to have over output. The setback of using SMPS compared to linear power supply is that it generates electrical noise which contributes to electromagnetic compatibility design issues & more part count. Buck Converter SMPS The SMPS circuit below from Power Integration makes use of LNK304 as its high frequency switch. Take note that this circuit is non isolated type which means tha...

Switching Power supply circuit produces a voltage B + (dc voltage) needed television series taken from the net voltage household. G7 G7A chassis and power supply circuit using cool / cold in which the primary and the secondary power supply electrically separated so that the chassis can be directly connected to another device via an audio video terminal. Switching power supply This power supply circuit is a type SMPS (Switching Mode Power Supply) using mosfet transistor integrated circuit voltage controller in one IC package, namely STR-W6654. This IC will control the duty cycle of time off Vth2 Mosfet transistor to control the output voltage. Besides, the IC is also equipped with a safety circuit against overvoltage (OVP), overcurrent (OCP) and over temperature (TSD) circuit is working on 220V ac voltage with the input ac voltage range of 176V to 260V ac or known by the Wide range Regulators. How to Work Series Initial bias voltage dc pin6 IC801 obtained from an ac voltage through D811...

DESIGN/SERVICE mode To enter the USER SERVICE mode Caution: The user service mode adjustment can be changed only when service personnel adjust the whole set data during servicing. As the control data have dramatic effects on functions and performance of the TV, service personnel should not tell user how to enter the SERVICE mode to avoid improper data settings. Set the volume to 0. Then press and hold the MUTE button on the remote control, and press the MENU button on the TV to enter the SERVICE mode. (In this case, the S mode cannot be stored in the EEPROM. To exit from the S mode, turn off the TV set.) After entering the S mode, Red“ S”is displayed on the upper center of the screen and MENU1 is default. Use the POS+/- buttons to highlight an adjustment and the VOL+/- buttons to adjust it. The adjusted data are immediately output and stored in the EEPROM. EX-1A1 chassis series are applied in 21NF55/21PF93 respectively which uses mainly Philips’ advanced UOC-ultimate chip TDA935X/6X/8X...