Questions tagged [lm78xx]
LM78xx are a popular series of linear voltage regulators. To name a few 7805, 7809, 7810
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Suggestions for dropping resistor on LM78 regulator
I’m trying to repair a magnetic stirplate (see http://staff.washington.edu/wbeaty/chem_stir.html). I found that in one part of the circuit it fails to deliver 12V. I’ve draw part of the circuit below:
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78L24 outputs high voltage >24v - Harman Kardon AVR 151
I'm trying to repair my broken Harman Kardon AVR151.
Looking at the SMPS schematic, to my very limited knowledge I do not understand,
The 78L24 is a high side 24V regulator.
Why does the schematic ...
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How to fix dc 12 led lights that burn out due to excess voltage or current
How to limit the output DC voltage to dc 12V if the input voltage is greater than DC 12v, and it outputs same voltage if voltage is below 12 V like 11.5 V or 10.5 V?
Scenario:
I have solar setup at ...
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Why does my LM7805CV output voltage drop at loads <= 150 mA?
According to this answer the LM7805 has no minimum load. The data sheet also indicates that the output voltage should remain between 4.8 and 5.2 V for output currents of between 5 mA and 1 A.
I have ...
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What are the disadvantages of using a Zener diode over a linear voltage regulator?
I wonder why a Zener diode is worse than linear voltage regulator.
Some of the posts online mentioned that because of the power dissipating problem. Zener diodes keep consuming a large amount of ...
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Does placing additional capacitors in parallel with CJ7805 affect its performance?
I'm not sure if this is a stupid question, but I'd still prefer to ask than regret it later. I'm designing a PCB with the CJ7805 which, like the LM7805, can supply a steady 5 volts. In this case, it's ...
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Using series of LM 78XX for power supply
I'm new in electronics. I want provide 9V (VVD9) and 5V (VCC) for my electronic board including power mosfets (IRF 3205), high power LED (14V-3.5A), micro-controller (at-mega16), and etc. I use this ...
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Zener Diode vs LM78XX
To get, say 5VDC, from the AC mains, after stepping down the high AC voltage using a transformer, we have to rectify it and regulate the output DC voltage. As I have seen, there seems to be two ...
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How much power does LM7805 dissipate?
I'm using an LM7805 in voltage regulator mode.
Vin is 15V
Vout is 5V (regulated)
The attached load draws 200mA
How to calculate how much power the LM7805 would dissipate in this setup (and whether ...
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Series pass transistor, LM7812
I am making a 12 volt regulator for a solar panel to power an audio amplifier. I already have a switching regulator for most application but it is very noisy for amplifier even with a lot of filtering....
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Connector acting as ground?
I am building a power supply using LM78×× voltage regulators.
The circuit works as expected with no load but when I connect the circuit to external connectors, LM7812 on circuit starts getting very ...
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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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LM7805 Voltage Drop too big
I setup the following circuit:
When I measure the voltage between GND and INPUT of the LM7805CV I have a voltage of 7.9V (around 8V as per power supply). But when I measure the output it is only 1.4V ...
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Voltage regulator replacement
I have a gadget (a Sonar) that stopped working (doesn’t respond to power on, power led does not turn on) and opening it to look for the typical signs of failure I see an L7818 voltage regulator in TO-...
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Connecting Voltage Regulators 7812 in Parallel for High Current [duplicate]
Could I use two L7812 voltage regulator ICs in parallel to get 12 volt and more current that with just one?
