Hello i have a 5v lt3045 based ps that i bought with the fixed set resistor as in the table datasheet.
I would like to get 1.8v instead of the 5v.
What is the correct resistor value to achive 1.8v?
Can someone help me?
Thks
I would like to get 1.8v instead of the 5v.
What is the correct resistor value to achive 1.8v?
Can someone help me?
Thks
18kohm..
Ciao, George
Ps: you can also control the validity of my 'thesis' - based on the same datasheet calculus (100ųA reference current)- - I tell You that You will find on the board presently a 50kohm set resistor.
Ciao, George
Ps: you can also control the validity of my 'thesis' - based on the same datasheet calculus (100ųA reference current)- - I tell You that You will find on the board presently a 50kohm set resistor.
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not a bad idea..
Also, while we are at it; that high impedance input is very sensitive to stray leakage currents, like those originating from the soldering flux deposited during your operation.
So wash thoroughly the board, with pure alcohol (isopropyl-alcohol..), afterwards. And dry it.
And be patient when trying after, it stil could be 'unstable', leaking, wait until it stabilizes.
Ciao! G
Also, while we are at it; that high impedance input is very sensitive to stray leakage currents, like those originating from the soldering flux deposited during your operation.
So wash thoroughly the board, with pure alcohol (isopropyl-alcohol..), afterwards. And dry it.
And be patient when trying after, it stil could be 'unstable', leaking, wait until it stabilizes.
Ciao! G
I ha some trouble with my board. It is unstable and can give from 3 to 5volts at the 5volt implementation with 49,9Ohm. I have resoldered all points and also checked values and components. Could it be flux causing this problem?
I never ever had flux problems with LT3042/45, and -if at all- I use a
isopropanol-wetted Q-tip if it looks too ugly. But then I don't use solder
for rain tubes.
Is the input voltage to the regulator constant?
The voltage over the reference resistor should be the same as the
expected output voltage. Measure with high impedance volt meter.
If you only have such a 20KOhm/V thingy include its value in the
set resistor.
If there is a capacitor across the reference resistor, you can remove
it for the moment.
isopropanol-wetted Q-tip if it looks too ugly. But then I don't use solder
for rain tubes.
Is the input voltage to the regulator constant?
The voltage over the reference resistor should be the same as the
expected output voltage. Measure with high impedance volt meter.
If you only have such a 20KOhm/V thingy include its value in the
set resistor.
If there is a capacitor across the reference resistor, you can remove
it for the moment.