Tagged Questions
2
votes
1answer
99 views
How to build “two power sources” in a microcontroller circuit?
My circuit has a microcontroller, it uses power from a DC transformer (120V to 12V DC). My circuit also control an pneumatic valve which also use 12V DC. Almost every time when the pneumatic valve ...
0
votes
0answers
53 views
LED display has noise
I am developing a LED display driver. It uses a PIC18F452 microcontroller and a 74hc245 IC.
It uses the SPI protocol to send signals to the LED display. When there are small number of LEDs switched ...
2
votes
1answer
64 views
What type of potentiometer to use for 240v AC power application?
I'm working on my first Raspberry Pi project which is to change the brightness of standard household light bulbs.
I have my Raspberry Pi and relay switches which together let me control when the ...
3
votes
1answer
93 views
ATX PSU 5VSB + 5V
Is it possible to connect both the 5VSB and 5V pins of an ATX PSU to provide +5V?
I would like to be able to initially boot using the 5VSB, which is always enabled. Once I've completed setup I would ...
2
votes
1answer
84 views
Power switching a higher DC supply from a mcu
I'm designing a pcb with a 3.3v mcu and some 5.5++V modules on it.
My microcontroller is doing the power-management, turning the 5.5V supply on/off. But I'm not sure how to turn the "high" voltage ...
1
vote
1answer
399 views
How to drive high power LED and Arduino by the same power source?
I am building a plant light consisted of 24 high power LEDs (Cree ML-E) and an Arduino Uno. I would like to power the LEDs and the Arduino by the same power source. Since creating circuits for dealing ...
5
votes
2answers
157 views
Pulse generator and source supply connection
I need a signal that most of the time will work as a power supply for the microcontroller but at some external event a positive pulse will be generated and added to the normal power supply. Power ...
-3
votes
3answers
99 views
Troubleshooting embedded system [closed]
I am in process of troubleshooting an embedded system.It has a 3.0V DC bus line. Accidentally I connected a 12V bench supply..after that the embedded system doesn't seem to be working at all. The unit ...
5
votes
2answers
174 views
How much power can reasonably be collected from ambient background radiation?
It seems that with a coil or simple antenna it should be possible to collect energy from the background 60Hz radiation in any modern home. How much could reasonably collected at low voltages (3.3-5V)? ...
0
votes
1answer
289 views
Microcontroller shutting down in etched circuit, but works as expected in breadboard circuit
I have a computer fan controller circuit which uses an microcontroller to convert an analog signal from a potentiometer to control the speed of an computer fan (PWM controlled) and indicate the rough ...
7
votes
1answer
177 views
Current flow priorities in PSU / PSU review
Being an electronics hobbyist, I'm having quite a challenge to design a PSU, which must run both on batteries (during the night time) as well as on Solar energy (daytime). The device is intend to run ...
2
votes
2answers
903 views
Can I use a microcontroller to control the output voltage of a switching powersupply?
I am attempting to control a switching power supply from my microcontroller. I am using a LT1377 from linear.
In the diagrams in the datasheet, a voltage divider is used to drive the feedback pin. Is ...
1
vote
1answer
220 views
Backup battery tester circuit
I am attempting to read the voltage on a backup battery on an Arduino. To that end, I used the circuit Olin Lathrop offered in answer to this question. I am powering the Arduino with 5V, and the ...
5
votes
5answers
444 views
Running my atmega8 at 5.5V, risky?
I have just received my first microcontroller, an Atmega8. I will soon be making a voltage regulation circuit for it to run at 5V, but I don't have all the parts yet.
Instead, I have a 5V DC 1000mA ...
0
votes
2answers
572 views
how switched mode power supply affect microcontroller functionality
I am using a switch mode power supply RAC06-05SC to power up the microcontroller (ATMega16L) a wifi module (RN-131G) and a 5V relay. This power supply is already regulated (as stated in the datasheet) ...
6
votes
4answers
1k views
Least expensive way to plug in a microcontroller into 120V (without wall wart or batteries)
I need to be able to power a Atmega168 by plugging it into a wall. The circuit is a little bit more complex but not too much. The Atmega168 needs between 1.8V and 5V at 200mA. The ideal solution ...
2
votes
2answers
93 views
How to power a low consumption Computer On Module from noisy industrial power sources
I am thinking about using a small Linux Computer On Module in an industrial environment. The specific application I need to use it for is in a panel that has limited power source options.
The only ...
2
votes
1answer
1k views
Transistor current limiter, microcontroller controlled?
I've come across a few transistor current limiter schematics, similar to this one:
However, I am not entirely sure how I could implement microcontroller functionality to control this. I think ...
4
votes
1answer
354 views
Dual power supply confusing TTL serial?
Sorry for the vague title: I'm a bit of a noob at analogue electronics, more a logic &software guy. Basic problem is I'm sitting at the end of a cable with a USB powered Arduino trying to send ...
1
vote
1answer
243 views
Arduino power supply issue
I've been playing with the ATmega328 and xbee a lot and wanted to take it to the next step and make it fully mobile. So i have decided to use 2xAA batteries along with a 5V step up to get a stable 5V ...
1
vote
2answers
521 views
How much current can I supply to power PIC12F675?
I have a power supply that outputs 5.9V at 375mA that I'm running through a 5V regulator.
I'm wondering if 375mA is too much for a PIC12F675? I dont want to fry this little guy.
If it's too much how ...
1
vote
1answer
502 views
Is this galvanic isolation?
I'm doing a project which consists of 2 big parts: a control part (a microcontroller with I/O pins expanded, USART-to-USB, a RTC, an EEPROM, a LCD) working @ 5V and an actuators part (optocouplers for ...
8
votes
1answer
806 views
How does this power supply circuit work? (MCU + LM317)
I've been studying this schematic that I found while searching the web. I understand the point of PWM - it allows us to vary the average voltage fed to the op-amp precisely. The filter R1,R2 and C1 ...
16
votes
1answer
3k views
How can I detect a power outage with a microcontroller?
I have the following power supply configuration:
AC MAINS -> UPS -> 24V POWER SUPPLY -> 5V VOLTAGE REGULATOR -> PCB (microcontroller).
What's the best solution to detect the power outage on the mains ...
2
votes
3answers
589 views
How can I design a robust and professional power supply circuit?
I'm planning on doing a large project that would include an ARM microcontroller @ 50 MHz interfacing with a graphic LCD, user buttons, some sensors and some actuators (DC motors, valves) controlled ...
9
votes
5answers
2k views
24VAC/5VDC power supply design
I am planning to create a water valve controller using an MCU and a set of solenoid-controlled valves. The solenoids run on 24VAC (40mA inrush, 20mA holding).
The MCU is on a board that draws ~100mA, ...
4
votes
5answers
2k views
Voltage regulation and current limiting with a microcontroller
I'd like to build a power supply for my desk. I've found a few projects based on the L200 adjustable voltage regulator.
In the example below, how could I replace R3 with a microcontroller, so that ...
9
votes
3answers
2k views
How to implement a soft power switch controllable by microcontroller?
I want to design a circuit such that the microcontroller can toggle a GPIO pin and shut the whole system (including microcontroller itself) down. And when the user presses a momentary button, the ...
5
votes
3answers
2k views
A better power supply for microcontroller circuits
I've been playing around with PIC microcontrollers for a while now, and have had a fair bit of success, however I sometimes get unexplained resets and sometimes need to cycle the power a few times to ...
3
votes
4answers
336 views
Delayed power supply startup
I would like to make a circuit that turns on a power supply to a microcontroller after holding down a button for a period of time (say 2 seconds). To make matters slightly more complicated, if ...
