- #1
roeb
- 107
- 1
I have a 24 V lead acid battery that I am going to use for a power supply. I need to get 5 volts so that I can power an AVR some other stuff. I was originally intending to use a 7805 to get 5 volts, but I am concerned that this may be too much power dissipated.
I think I need about 200-300 mA and I am I not mistaken that is 19V * 300mA = 5.7 W which is awfully high. However, we do essentially have a very large heatsink that we can use because this will be attached to a large metal frame, but I think that may still be too much...
It was suggested to me to use a switch mode power supply, but unfortunately, I think be both too costly as well as taking up too much space.
Would a power resistor and a 1 W zener diode be a better choice than the 7805?
Does anyone have any suggestions for what I can use to get a steady 5 volts? ( I cannot compromise on the 24 V source)
I think I need about 200-300 mA and I am I not mistaken that is 19V * 300mA = 5.7 W which is awfully high. However, we do essentially have a very large heatsink that we can use because this will be attached to a large metal frame, but I think that may still be too much...
It was suggested to me to use a switch mode power supply, but unfortunately, I think be both too costly as well as taking up too much space.
Would a power resistor and a 1 W zener diode be a better choice than the 7805?
Does anyone have any suggestions for what I can use to get a steady 5 volts? ( I cannot compromise on the 24 V source)
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