Hello my friends.
I'm writing from Argentina. I ask for help. I want to build a low noise regulator to replace a L7805. Not fluent in English and that makes clear what I read in this forum. The intention is to build, not buying a super regulator.
Someone can help me get a low-noise circuit to replace my current regulator?
The current requirement is 200mA.
Thanks my friends!
Matias
I'm writing from Argentina. I ask for help. I want to build a low noise regulator to replace a L7805. Not fluent in English and that makes clear what I read in this forum. The intention is to build, not buying a super regulator.
Someone can help me get a low-noise circuit to replace my current regulator?
The current requirement is 200mA.
Thanks my friends!
Matias
PCB for teddy's 'Regulator booster' - pink fish media
Not sure if this can handle 200ma, but it can handle well over 100ma. Its a drop in replacement. You just make the simple circuit, and plug it in where your 78XX used to be.
Not sure if this can handle 200ma, but it can handle well over 100ma. Its a drop in replacement. You just make the simple circuit, and plug it in where your 78XX used to be.
Hi
For a positive supply Use a common collector NPN transistor regulator, with two resistors between the collector and base, midway between these resistors use a 2.2uf cap observing its correct current for a 1 watt zener of 5.6v. for 12volt supply use 2x 15 ohm resistors between the collector and base , choose a transistor suiting the current requirements. Between the base and ground parallel with the diode use another 2.2uf cap. This will then have a very low ripple output.
A BD139 has quite a bit more current than 200ma but can be used with some series resistance on its output if needed if you have a specific 200ma requirement.
The emitter then - its output of the BD139 should be very close to 5volt for a 12 volt input. Its very late here in Australia, but I can draw a schematic tomorrow.
Cheers / Chris
For a positive supply Use a common collector NPN transistor regulator, with two resistors between the collector and base, midway between these resistors use a 2.2uf cap observing its correct current for a 1 watt zener of 5.6v. for 12volt supply use 2x 15 ohm resistors between the collector and base , choose a transistor suiting the current requirements. Between the base and ground parallel with the diode use another 2.2uf cap. This will then have a very low ripple output.
A BD139 has quite a bit more current than 200ma but can be used with some series resistance on its output if needed if you have a specific 200ma requirement.
The emitter then - its output of the BD139 should be very close to 5volt for a 12 volt input. Its very late here in Australia, but I can draw a schematic tomorrow.
Cheers / Chris
There are hundreds if not thousands of ICs that can give 5V output @ 200mA with only a few additional parts and do it with same or lower noise than LM7805. Check your local electronics distributor, there are so many they won't even know where to start suggesting them unless you come up with more criteria than just 5V, low noise, and 200mA.
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