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lm317+zener
Hey Ian,
I guess I have to ditch the old design because I could not heat the circuit for heat test. It seems that the heat generated from the circuit is killing the current draw and it stops working when I increase the heat to 90 degC.
Anyway, I have another design that I am...
I was thinking of designing a MOSFET buck high voltage regulator with:
Input of 70V and output of 20V and load current of 0.5A
I designed a circuit using a darlington BJT transistor to buck the voltage to 36V and regulate the voltage to 20V using a LM317T.
It seems the linear voltage design...
lm 317 applications
I was wondering if I could use a TIP120 instead of a TIP102.
Will the TIP120 burn on when I supply a 70V and loading 500 mA to the first stage of the circuit?
lm317t applications
IanP
I dont know if the BZY Zener diode would be available anywhere, do you have an alternative to the Zener Diode other than the bzy?
what do you mean when u say a smaller zener diode with an external power bjt?
is that an aditional darlington bjt?
lm317t application
Thanks for the quick reply, I do not experience with the darlington BJT, what values of R should I use?
Added after 16 minutes:
Okay I did look up on the TIP1102, and it is totally different from the schematic that you gave with a diode and 2 extra resistors on the TIP102...
lm317 application
I am trying to build a step down voltage regulator using the LM317T.
What I have designed, is using 2 LM317T chips. The input voltage is a 70-77V battery.
The first chip will step down the voltage to 35V and the second chip will step it down to 21V.
When I tested the...
Hey I need some help, I already stepped down the voltage to 37V but now my problem is I can't draw current up to 0.3 A on the Voltage Regulator design that I made. The maximum current that can be drawn on this circuit is 0.14A. If I draw more than 0.14 A which is up to 0.27A, the output voltage...
I guess the datasheet did not specify the output voltage or i missed it out.
Thanks for helping me out. This is my first time posting on a forum. Will try that out.
The Vin-Vout of the first chip is 70-42=28V and the second chip is 44-20=24V.
The 70V supply can provide a max of 7A.
I used a decade box to provide the load to the circuit.
I am building a Step Down Voltage Regulator from 70V to 20V using 2 LM317T chip. The schematic design is attached with this post.
The problem I am getting is whenever I load with the circuit with 0.3-0.5 amps, the voltage is unstable where the output drops from 19.85V to 10V.
On the...
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