Recent content by singonn2

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    0-30V Stabilized Power Supply

    hi everyone , now i doing new 5A power supply project  using schematics and part list provide by redwire in first page . now i meet a problem , the LED is light while i switch on power same as noworries , i still using 24VAC 3A transformer for a test before get a new 30VAC 5A transformer...
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    Led display Digital Voltmeter question

    isn't the display voltage unstable because the resistor 5%-1% relation?any pro answer it ?
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    0-30V Stabilized Power Supply

    guru isn't i can connect the fan cooler to the line about 3xV after bridge rectifier and add a resistor for reduce the voltage to the fan. half-wave rectification ripple is too high, i hope the fan wont easy mangle, for economize diode and circuit can just borrow the current from bridge...
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    0-30V Stabilized Power Supply

    I will try it thx guru. ;)
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    0-30V Stabilized Power Supply

    thx for guide guru, the transformer i already series for gain 24VAC isn't i can pull one more line from one of 12VAC with a diode mean half-wave rectification = about 6VAC? the return circuit of the fan is point to the return circuit of transformer?because when i series the transformer 12V+12V...
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    0-30V Stabilized Power Supply

    guru my transformer is 12+12V=24V ,after bridge rectifier is about 36V actually need how much input voltage for LM317HV to gain 12V with about 0.5A and  the watt is lowest. isn't LM317 input about 12-13V output will 12to13V also?
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    0-30V Stabilized Power Supply

    thx guru.Both method need a heatsink again  :-\ now my problem also hard to get a pretty big heatsink , heatsink is also quite exp , LM317HV 12V with mA also will very hot?can i just put it circuit on a perfboard and cooling with fan cooler also?the input of LM317 can i just borrow the current...
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    0-30V Stabilized Power Supply

    sorry , i mean i hope add a fan cooler for the ps with using the voltage and current from U1 output isn't okay?or other ideas without using 2 power supply for the fan cooler, because my heat sink quite small so i add a fan cooler.
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    0-30V Stabilized Power Supply

    i think need make a FAQ about this power supply project because it's a lot newbie doing it. guru can i put a cooler on U1 output ? or other ways without using 2 power supply for add the cooler.
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    0-30V Stabilized Power Supply

    ya,one of it,after i replace U2 with TL081 the voltage is like my notion as u say higher voltage than output voltage,isn't TL081 can replace with TL082 ?sry for my bad english. the LED is always light up now i see , i had put the Q4 on a heatsink + a fan on it , 26W wont reach 200*C is...
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    0-30V Stabilized Power Supply

    thx guru the fringe problem is fix reason was a ic741 was burned , from original circuit U3 output voltage is about 30VDC and U2 output voltage along with the supply voltage change isn't correct? the ripple can check with electric meter ? if the digital electric meter show the voltage is fix...
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    0-30V Stabilized Power Supply

    i using 24VAC with 3A isn't can replace TL081with741? , the led is no light up , isn't the leb light up while DC output short circuit ? the C1 voltage is 33VDC the output of U1 is 11VDC and the -5.6V voltage there is -5.6VDC also it's correct?the point i check the voltage of -5.6V is between R3...
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    0-30V Stabilized Power Supply

    thx guru
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    0-30V Stabilized Power Supply

    can someone post the full different effect btw the old version  0-30V Stabilized Power Supply with current control and the new updated version? please replace the older version if it's unsafe or too much bugs cos it really make newbie lik me confuse  :-[ isn't the older version totally unable...
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