Questions tagged [lm78xx]
LM78xx are a popular series of linear voltage regulators. To name a few 7805, 7809, 7810
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LM78xx Reverse Polarity and Reverse Bias
I'm building a circuit that will use a LM7805 and LM7812 to produce 5VDC and 12VDC respectively, with the input power being ~16VDC from an external wall wart.
I already fried one of each regulator ...
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7809 Linear Voltage Regulator Outputs in Series
I'm building a linear power supply that converts 120VAC mains voltage into multiple 9VDC, isolated outputs. I'm using this transformer that has the proper primary winding and 8 secondaries that I'll ...
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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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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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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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LM7915 delivering more than -15v
I'm trying to build a regulated power adapter using LM7915.
Before everything, I built on a protoboard the schema included on the datasheet (from ST). But, instead -15v, the output is -19v...
I'm ...
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78L05 questions [duplicate]
What are the capacitors on the input and output of a 78L05 for?
I saw a lot of different schematics with a lot of different input and output capacitor values.
So now I am really confused, and I'm ...
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xV input from a wall wart to +9v, -9v, +9v output
I am trying to modify a circuit Circuit schematic that requires three 9v batteries. Two to supply +9v/-9v for an lm358N opamp, the other +9v is to drive a DMM display.
I have dozens of wall warts of ...
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buck converter and regulator
First:
I want to use DC DC Stop Down Buck Converter, im using this one:
- https://www.aliexpress.com/item/10pcs-24V-12V-to-5V-3-3V-3V-DC-DC-1A-Step-Down-Converter-Voltage-Regulator/32671102728.html
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LM338T Output to 5V issue with LM1085-IT 3.3V
I am using 12V , 2A DC power supply as an input to LM338T and LM1085-IT 3.3 , for 5V and 3.3V output respectively.
The issue i am facing here is when these both voltage regulators are connected in ...
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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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Lm7812 circuit help
In circuit to get a steady 12v DC I don't understand the use of the capacitors. Can anyone help me?
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