Micro Supply [170464]
This adjustable power supply for IoT device development provides 0 to 5 V in 50 mV steps, measures current from 0.5 uA to 20 mA, limits current at 20 mA.
Micro Supply
Connected objects require adjustable voltages and very low current measurement during its development. I propose a card that goes on an Arduino Leonardo.
Characteristics :
- 5 Volt power supply from USB port via Arduino Leonardo
- 0 Volt to 5 Volts at 0.05 Volt pitch with memory
- Software shutdown of the power supply if the current is greater than 20mA
- Display of selected voltage
- Display of current from 20mA to 0.5μA
Connected objects require adjustable voltages and very low current measurement during its development. I propose a card that goes on an Arduino Leonardo.
Characteristics :
- 5 Volt power supply from USB port via Arduino Leonardo
- 0 Volt to 5 Volts at 0.05 Volt pitch with memory
- Software shutdown of the power supply if the current is greater than 20mA
- Display of selected voltage
- Display of current from 20mA to 0.5μA
Discussie (1 opmerking(en))
JPe4619 7 jaar geleden
Why 20mA limit? Would prefere a wider range (200mA) so you can experiment with several settings and programm details for low(er) power use.
Antwoord
Aubinais 7 jaar geleden
Thanks you for your comment.
The object is to make a very low current power supply because my IoT projects often have to consume less than 1mA and see 0.5uA ;-).
If this project makes to 200mA:
- A looped transistor should be added to the output of the AOP.
- It is powered by a voltage doubler to be sure to have 5 Volt so this circuit should be completely redone.
- I use a resistance of 10Ω to measure the current which still makes maximum 0.2 Volt loss at the output. In the case of 200mA, a switching must be implemented in order to use a resistance of 0.1Ω for example.
This really complicates my initial project.
Best regards
The object is to make a very low current power supply because my IoT projects often have to consume less than 1mA and see 0.5uA ;-).
If this project makes to 200mA:
- A looped transistor should be added to the output of the AOP.
- It is powered by a voltage doubler to be sure to have 5 Volt so this circuit should be completely redone.
- I use a resistance of 10Ω to measure the current which still makes maximum 0.2 Volt loss at the output. In the case of 200mA, a switching must be implemented in order to use a resistance of 0.1Ω for example.
This really complicates my initial project.
Best regards
Antwoord
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Updates van de auteur
Aubinais 7 jaar geleden
The first PCB project works very well. I use it every days for BLE projects and LORAWAN projects. I didn't know how to use the switch but it allows to select the circuit software breaker at 20mA. For exemple, the LORAWAN Node has a current peak at 40mA without break.
You can see any errors have be correct on this PCB and correct on the new schematic.
I made some modifications for the next schematic :
- don't not use a JST connector but a classic connector. I still use the USB connector.
- even if there is a voltage regulation, the voltage will be measure and display. If the voltage is very low (short circuit), the breaker will be actived.
- the current measure and the voltage current will be send each milliseconds to the Arduino serial port to the computer.
Best regards
Jennifer