I sometimes use things like R13 and R14 when the supply voltage is a bit too high. I calculate that at maximum current of 1A (for example), a reaonable voltage drop across the input resistor to keep the input voltages to regulators about 3V-4V above the regulator output. Simply put, I make the resistor dissipate the heat instead of the regulator. It does have limits, as the resistor has to handle a watt or two (or 3) of heat, which the regulator no longer has to handle. It makes heatsinking the regulator a bit easier. Higher wattage resistors are relatively cheap. Mind you, your enclosure has to handle the heat eventually, from both devices.You can delete R13 and R14. But first, please explain why you think they are needed.
I don't like to add the output caps to the 5V chip in the 1st way, that is why i place the 5v chip directly after 12 chipDo add the output caps to the 5V chip in the 1st way.
The maximum loads required for each regulator:What are the maximum loads required for each regulator?
Like he sagor Said:you can delete R13 and R14. But first, please explain why you think they are needed.
I am using a center-tapped 12Vac, this supply voltage is a bit too high; I thought using the resistors for dissipate the heat instead of the regulator, I and because resistors are relatively cheap then regulator and easily replaced then ,I sometimes use things like R13 and R14 when the supply voltage is a bit too high………….Just an opinion...
Yes i use a center-tapped 12Vac I keep one for another separate high loads as small motors and other things like lamps!!Where is the AC coming from and what is its voltage? .
Your information isn't easy to decipher, but having the 5V regulator input on the 12V regulator would probably be best.The maximum loads required for each regulator:
1- +5v for three voltage divider there inputs are in lm324n both (inverting and no-inverting), 2 leds
2- +12v is for lm324n as comparator and amplifier, relay (400 ohm)
I don’t think that I have big loads!?
I am sure that I need +5v regulated and fixedMaybe you only need one DC voltage supply.
Please can you help me to fix the problems of the reverse conduction of leds and about leds I want to add two leds one green and the second red1. Unless the LEDs are an indicator type with built-in current limiting, you need to add a current limiting resistor in series with each one.
Thank you I can fix that3. You should add a suppression diode across the relay coil, something like a 1N4004, to protect Q1 when the relay is turned off.
I don’t like to add the output caps to the 5V chip in the same time I want to keep the good regulation given by 12v chip and his capsYour information isn't easy to decipher, but having the 5V regulator input on the 12V regulator would probably be best.
i am just a beginner in electronic all what i want to do is to go step by stepWhy are you so sure that you need +5V?
Why does LM324N need +12V?
I have >1001 components. I don't use them just because I have them.i am just a beginner in electronic all what i want to do is to go step by step
i have read some where that Absolute maximum rating of Lm324 is 32v
i just choose the +12v because i have 12 chip regulator, i have +12v relay and i have other loads which need +12v
i just choose the +5v because i have 5 chip regulator, and after tests i concluded that +5v is good for my applications
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