Linked Questions

-1
votes
1answer
325 views

Switching from battery to usb power source [duplicate]

I'm currently creating a small device to operate on a CR2032 battery when it is disconnected and a USB power when it is connected. I want the device to be powered by USB when it is connected, without ...
0
votes
0answers
25 views

LDO with 2 input sources [duplicate]

The following LDO is supplied from 2 input sources. BAT, which is a battery from 2.5-4.2V and VBUS, which is a power adapter voltage of 12V. My understanding is that a diode has a forward voltage drop ...
7
votes
4answers
10k views

Switching between battery and USB using diode OR logic

I have a Raspberry Pi that is powered by a USB cable from a Samsung charger. Now since my college has frequent power cuts, I designed a basic switch to automatically switch between a portable mobile ...
6
votes
2answers
12k views

Switch between battery and USB power

Following on an earlier question I am looking for a circuit where it powers from USB when it is available and uses the battery when USB is not plugged in. I want voltage drop to be minimal, zero if ...
2
votes
2answers
3k views

12V Battery Backup Supply for GPRS Tracker

I have little knowledge on electronics apart from following a few guides. I have made a few 7 segment displays, nothing complicated. Recently my girlfriends car was stolen and she has an insurance ...
0
votes
1answer
4k views

P-chanel MOSFET series configuration

Good day I'm busy designing a small DC UPS to run some appliances when the power goes out. I am, however, having trouble with an element in the battery switch-over circuit. I decided on using a ...
0
votes
3answers
1k views

power selector switch [closed]

i'm still working on my usb meter. I still have a problem in my design, I would like to implement an external power supply and a battery. I was looking for a circuit that would switch automatically ...
1
vote
1answer
481 views

Intel Atom board (DN2800MT) power supply, can I add battery?

After reading through 20-something posts about 'car/12V/power supply/computer' I've still not found a definitive answer to what I'd like to try here. If this turns out to be a dupe after all, my ...
1
vote
1answer
382 views

Choosing the right FET to switch between two sources

The circuit below is based on the answer to this question, which i find to be suitable for my application. 3.3VDC is the main supply for the circuit, with 3.6V 1/2AA battery for backup, as defined ...
0
votes
1answer
131 views

What is the simplest and best device (or circuit) to stop the flow of current in a line when current in another line is present? [duplicate]

What is the simplest and best device (or circuit) to stop the flow of current in a 3.7V (2A) line when current in another 5V (2A) line is present? Basically I want to make an UPS using a LiPo battery ...