Power Transistor

How PNP power transistor amplifies the current? Then why is it called power transistor?

How PNP power transistor boost up the current, the current is boosted at the cost of voltage? Suppose we use 12V dc as power supply, then if we use power transistor, will it reduce the voltage given to circuit to less than 12V and amplifies the current?

i think power transistor increases ur voltage.well exactly i dont know the correct answer!!!

Cobra HG-M75 4-Pin CB Radio Microphone with Powered 2 Transistor Amp with Gain $15.95

NTE181MP RCA SK3037 2N5885 Power Supply Transistors Kenwood TS-940S $6.00

5p Mitsubishi NPN 2SC1946A C1946A RF POWER Transistor $107.98

5x Motorola M1570 MRF1570 RF Amplifier Power Transistor $175.00

RCA Silicon Power Transistor Guide 1950s $1.99

Vintage TR-1 Westinghouse 9 Transistor Battery Powered Transceiver Set w/ Boxes $8.00

MJE 803 Power Darlington Transistor ( 10 pcs ) $4.49

TOSHIBA 2SC2879 POWER AMPLIFIER TRANSISTOR – CB HAM – BRAND NEW – NEVER USED $33.00

KT962A – 17W Si NPN UHF RF POWER TRANSISTOR – NOS GOLD $5.00

KT930 120W + KT920 UHF RF POWER TRANSISTOR – NOS GOLD $10.95

CB Parts- ECG 152 – 7amp-50 watt Power Transistors, 3pcs. NPN $6.79

Motorola MRF240A power transistor RF finals (HTX-242, HTX-212 for example). $5.50

10 PCS!!! NEW TOSHIBA 2SC2641 UHF 6 WATTS+ 12 VOLTS POWER TRANSISTOR,SHIPS INTL! $19.90

4 PCS!! NEW NOS MOTOROLA M9780/2N6080 6+ WATTS VHF 12 VOLTS RF POWER TRANSISTOR $9.95

3pcs Mitsubishi NPN 2SC2694 C2694 RF Power Transistor $85.99

5 Motorola M1550N MRF1550 RF Amplifier Power Transistor $212.00

2pcs Mitsubishi NPN 2SC2630 C2630 RF Power Transistor $59.00

20pcs Mitsubishi NPN 2SC2694 C2694 RF Power Transistor $524.99

2p Motorola MRF485 RF Power Transistor 30MHz TO-220 NEW $31.88

2p Mitsubishi NPN 2SC1946A C1946A RF POWER Transistor $44.88

CB Parts- TIP41 6amp – 65 watt Power Transistors, 3pcs. for Cobra-Galaxies $6.49

CBS-Hytron Bulletin E-285 1958 Transformer Design Notes Transistor Power Supplie $0.99

CBS-Hytron Bulletin E-281 (1957) “Transistor Power Supplies” by Bud Tomer $1.99

MRF 455A RF Power Transistor. Used in Ten Tec Scout 555 and others $42.99

2/ea IRF520N – POWER MOSFET RF TRANSISTORS – BRAND NEW – SUB FOR ERF2030 IRF 520 $2.75

2SC2166 RF POWER OUTPUT TRANSISTORS (1 PC) $7.00

2SC1969 RF POWER OUTPUT TRANSISTORS (1 PC) $10.00

2SC2312 RF POWER OUTPUT TRANSISTORS (2 PC) $18.00

PA Power Transistor. Original Ericsson Part No. 19A134430P2. T,PWR, PA. $7.95

Ericsson/GE Power Transistor. Original Ericsson Part No. 19A700081P3 T,PWR. $9.95

4800869860 RF POWER TRANSISTOR M9860 $16.80

4 x BLY84 transistor 250MHz / 12 W / VHF power amp. $11.00

3 x BLX91A UHF 4W Power transistor NOS $10.00

1X Motorola MRF9120 RF Power Field Effect Transistor $19.65

1X Philips BLF1820-90 UHF power LDMOS RF transistor $31.85

KT931A 150W + KT925B UHF RF POWER TRANSISTOR – NOS GOLD $14.95

1piece Philips BLF242 VHF Power MOS RF transistor $45.50

1X Motorola MRF19060 Power Mosfet RF transistor $33.66

10 Motorola MRF286 Power Mosfet RF Transistor N-Channel $218.40

1X Motorola MRF20060s RF Power Bipolar Transistor 60W $30.03

Motorola MRF284sc Power Mosfet RF Transistor N-Channel $13.91

1X Philips BLF2043F UHF power LDMOS RF transistor $22.75

5pcs MRF648 NPN SILICON RF POWER TRANSISTOR $95.55

1X Motorola MRF21030 Power MosFet Transistor N-Channel $13.64

BLF175 HF/VHF power MOS transistor $40.95

5x MRF247 NPN RF – Power – Transistor 75W 136-174MHz $81.90

1X Mitsubishi NPN 2SC2540 RF POWER Transistor 40W $19.25

1X Ericsson PTB 20151 PCN/ PCS Power Transistor $9.51

1X Mitsubishi NPN 2SC5125 C5125 RF Power Transistor $30.53

1X Mitsubishi NPN 2SC2694 C2694 RF Power Transistor $32.75

High voltage transistors are transistors with further specification of normal transistors. It is usually located in the power transformer, as the switch-mode power converter and flyback. On television and a monitor that uses the flyback high voltage to generate a high voltage transistor is required to do the job. Its location next to all the flyback and attach to a heat sink for transferring heat faster. Otherwise, you may blow at a time very short due to the hard work of the switching transistor. Typical number of high-voltage transistor that is used in the monitor and TV is BU2508DF, C3998, C5148, C5047, C5589, C5803, etc. Usually its rating of volts, amps and watts is volts and above 1500, 10 amp, 50 watts and more. Their sizes are much larger than the transistor signal. If you are short on high-voltage transistor, you have to find the exact number of spare part for the computer to last longer. Change in number usually will not last long, perhaps within weeks or months of time and it will fly again unless you know the storage and fall time of the transistor.

Higher voltage, amps and power does not guarantee that the transistor will not last long. Often a further specification blow in a fraction of seconds when turning on the computer. You have to go to that particular manufacturer for the transistor data sheet specifications and find transistor. Downtime for and value of storage time. The original and the replacement value of tolerance should be no more than 20%. If no replacement is the transistor will run hot and eventually blow the transistor. This will waste your precious time.As why sometimes even the closest transistor specification is also not working well because the team in particular as a monitor of the yoke and flyback coil is designed based on the specification of the transistor.

Thus, only the original number of transistors that can be installed on that computer in particular. I have seen even the original number of transistor with different lot when installing on the monitor screen causing the curve in (pincushion out) and the transistor runs very hot. I have checked all the circuits and components that connect the transistor to be well. Even replacing the flyback not help either. The transistor temperature continues to rise and if not turn off the monitor, I finally hit the transistor. I took the transistor and compared with the original logo and discovered that the replacement is a bit different from the original transistor logo. When I called my provider of electronics on the logo, which says that the transistor that I bought is a newer version, the thought of the same factory. After an hour long search for the original transistor, I managed to find one. Incredible, replacing the original transistor runs cool, the image is perfectly fine. Guess what is the number of transistors high voltage part? He C5148!

In another case, had a monitor came with no sign of power. After carefully checking the area of high tension, they confirmed that only HOT shorted without causing power. After substitution (the number was BU2508DF), when the monitor is turned on, opening and close energy. I thought I had some other bad components are causing the power to open and close. I check again the power and high voltage section but could not locate the fault. I took the heat that had to replace and realize that was a little different from the original. I took another hot that is exactly the same as my compartment spare parts and ready the monitor works perfectly well. I begin to compare hot and you can clearly see the different from the image shown below.

The lesson I learned from this mistake is always to replace an original part number (if possible) and not buy any component that is cheaper than the price open market.

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Article Source: ArticlesBase.com – Understanding The High Voltage Transistor In Computer Monitor