Tagged Questions

1
vote
1answer
77 views

Linear useage of excess power generation

A friend of mine is fortunate to have moved to a very warm and sunny country, and has installed a photovoltaic system on his property. This is grid tied and any excess that he generates flows into the ...
6
votes
4answers
224 views

Protecting Microcontroller Input Pins from Soft Power Switch

I'm working on a soft power switch for a microcontroller where a momentary switch can turn the circuit on (including microcontroller), and then when the switch is pushed a second time, the ...
3
votes
1answer
96 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 ...
0
votes
3answers
169 views

How to control 0 to 110 of AC with microntroller rms output of 0 to 5 v

Is it possible to control high current with small rms voltage? UPDATE Do you think that this is gonna work?
5
votes
1answer
132 views

Any disadvantages to single-supply mode?

I am using the ATMEL ARM SAM4S MCU for a project. It supports a single-supply mode where an internal voltage regulator provides the 1.08-1.32V necessary for VDDCORE and we need only provide 1.62-3.6V ...
3
votes
2answers
85 views

Connecting powered digital IC to unpowered

I have Atmega328 MCU and MAX7219 connected to each other. However, they have diode separated power sources. There is a case, when MCU will get power, but MAX7219 will not. Would it damage MAX7219? ...
2
votes
1answer
178 views

SMALL BOX Solution - To control/reduce power consumption in household electrical appliances?

We use multiple power sockets to power different house hold electrical appliances like.. AC, Refriegerator, Television and Other Electrical Appliances. I want to turn on/off their power ...
1
vote
1answer
209 views

P-chan MOSFET as power switch

I want to create a power switch (on/off) for a hot-swap plug-in module that connects to my (future) PCB. Got a MCU on board and a single 3.3V supply, fed from AA batteries with through a DC/DC, this ...
4
votes
2answers
458 views

How to detect SD Card Insertion Without Leakage Current

I'm using a TI CC1111 SoC to read/write a microSDHC SD card, with an Amphenol card socket. The card detect (CD) pin of the socket is connected to ground when no card is present. When a card is ...
1
vote
2answers
524 views

How do I calculate how long my robot's battery will last?

I am building a robot with multiple types of sensors, 2 motors for locomotion, and 2 motors to control a robotic arm. I am using a variety of color, IR, tilt sensors and such. How would I factor in ...
6
votes
2answers
333 views

How to measure power consumed by mains device

I would like to measure the power consumed by a mains device. I have heard that it's not as trivial as simply measuring the average current, as the device may be resistive, capacitive or inductive, ...
3
votes
2answers
307 views

Classification of VDD and VSS pins

I am creating a library component for KiCAD using a convenient online app at: http://kicad.rohrbacher.net/quicklib.php. The component I am making is the Microchip PIC24EP512GU814 in LQFP ...
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 ...
0
votes
2answers
323 views

Measuring power/current

I was wondering if someone knew how to measure power/current and then interface it to a micro controller to store the data onto some external memory. I basically want to measure the power a device ...
1
vote
2answers
455 views

Custom switched-mode power supply or UBEC?

I'm in the process of designing a small, 5x5cm ATmega1284P-based microcontroller board. I would like it to regulate 6-18v input to 5v output, with a max continuous current rating of 1.5A. At first, I ...
3
votes
2answers
1k views

3.3v to 5v Translation

I'm in a bit of a pickle here. I need to translate 3.3v to 5v ttl levels. The devices I'm driving (12 total) are not low current devices so I don't want to interface directly, even with a current ...
3
votes
3answers
284 views

Powering microcontroller off USB, load off wall-wart

I'm developing a light display thing using a Teensy 2 and a digitally addressable LED string that draws quite a bit of power, more than can be provided over USB. I have ordered a switched wall-wart ...
6
votes
2answers
513 views

microcontroller low battery indicator

I am powering a board and circuit with a 9V battery (those alkaline ones). And I would like to read the 9V battery to keep track of how much power it has left. I have read that I can do this with a ...
2
votes
2answers
201 views

Atmel AVR32 UC3L Measured Power

Does anyone know of power-estimation spreadsheet or tool, or have measured power data for the Atmel AVR32 UC3L Series when running heavily in a real application? The datasheet itself is not very ...
4
votes
3answers
483 views

Design considerations for micro dc to three phase ac AVR based (ESC) for miniature UAV applications

This is a huge question, I plan to present the problem in detail and my current plan of action for solving it. I'm hoping to get pointers on what to and not to do. I was involved with a recent ...
0
votes
1answer
501 views

What Happens When You Exceed a Solid State Relay's Max Amps?

Had a quick question. I am using a Crouzet GA8-6D05 SSR to relay xmas lights for the holidays. I basically hacked an extension cord (120VAC US <1Amp) to do this. I am currently using a spliced ...
2
votes
2answers
166 views

Is there a hobbiest's source for Akros Silicon PoE evaluation boards?

I am interested in experimenting with PoE for a variety of small embedded controller projects. Is there a hobbiest's source for any of the Akros Silicon PoE evaluation boards? Or is there another bit ...
6
votes
3answers
1k views

Wide voltage supply for PIC microcontroller

I am looking to power a PIC microcontroller with a supply voltage that ranges from 4.5V to 18V. This will be a battery powered device so I would like to conserve power, ie. linear regulators like the ...