Questions tagged [lm78xx]
LM78xx are a popular series of linear voltage regulators. To name a few 7805, 7809, 7810
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Dual power supply, AC to ±12V DC, based on LM7812 + LM7912
I'd like to build a power supply, based on the LM7812 and LM7912, that outputs both +12 V and -12 V. I found this circuit online:
According to the datasheets, the LM7812 has a typical dropout voltage ...
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Why is the LM7812 getting hot in this circuit?
I have made this circuit. It works fine with normal Zener diode, however when I replaced it with the LM7812 it works fine but as time passes the regulator keeps getting very hot although the load is ...
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Make a switchable steady 5 V output circuit
I am looking to make a very accurate steady 5V power supply that can be switched on and off using the digital IO pins on an Arduino. I planned to use a 9V power supply connected to a 2N2222 transistor ...
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What could have caused my power supply to fail?
I made a dual +/- 12 V power supply for synthesizer circuits using a schematic by Moritz Klein (image below). The input of the supply is from a 12 VAC transformer.
After soldering the circuit on a ...
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In which option, the diode will make the lm78xx circuit safer
This image was taken from Fairchild's datasheet on lm78xx. I have already built a working example of it, but I am still thinking about adding some additional diode protection (D1, D2). Which option ...
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LM7805 decoupling capacitors
Would it be possible to replace these combinations of ceramic and electrolytic capacitors with just a pair of low-ESR 10 μF ceramics?
Conversion from 12 V to 5 V, minimal consumption, only MAX485 ...
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A question about 78XX power supply design
I want to get 12V and 5V from a 24V power source. 12V drives a MOSFET H bridge and a cooling fan. 5V is for a microcontroller. I have already damaged a microcontroller due to a failed 7805 regulator.
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Applying 5V on output pin of LM7805 while the regulator is not powered
According to the Datasheet of LM7805 (section Application and Implementation), in some scenarios a protective diode (between IN and OUT pins) is needed to protect the regulator.
Please take a look at ...
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Help me understand the calculation of the current consummated by LM7805
Please help me understand how to calculate the current consummated by LM7805 during its work.
Parameters:
V(in) = 12V
V(out) = 5V
I(load) = 10mA (0.01A)
The image ...
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Can LM7805 take 30 V max as input if the load current doesn't exceed 50 mA?
Can I use a simple LM7805 for my beeper hobby circuit that monitors a 30 V battery?
The load current doesn't exceed 50 mA.
It seems the IC will dissipate (30-5)*50 mA = 1.25 W worst case.
Will the IC ...
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Why does the LM7805 heat up? [duplicate]
I'm really not comfortable with things heating up, including this LM7805 integrated circuit wired below.
Why does this mighty LM7805 heat up?
Thank you for the help!
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Transistor for increasing current output of linear voltage regulator
Based on a suggested circuit from the datasheet, supplied current of LM7805 voltage regulator can be increased.
I can't source that BD536 PNP transistor or any equivalent listed on some websites.
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Can I somehow make the LM7805 work hand in hand with an N-channel MOSFET to get more current out of the regulator?
I've seen the circuit with the LM7805 being used hand in hand with a PNP to provide more current.
My problem is the heat that comes with said configuration. Isn't there a way to make a linear ...
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Which capacitors to use with voltage regulator IC such as 7805?
Many of the tutorials suggest to use a large smoothing capacitor (tens and even hundreds of uF) with a full wave rectifier but the datasheets of the voltage regulators and some tutorials suggest only ...
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how to calculate C for lm7809?
I need to use a LM7809 to reduce 12-14V to 9V , the device is using 40mA at normal state
when I search google for application circuit - I got all kind of valus for Cin , Cout. use this datasheet
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