Make 5V constant DC power supply (I=500mA)

Thread Starter

Zeeshan Ahmed

Joined Jan 19, 2011
1
hEY ALL OF YOU GUYS.....i had been given a project in which i want to make a contant 5V DC power supply....help me and give me full details or a good link about it for help...this is my first project......thnk you.,...
 

wayneh

Joined Sep 9, 2010
17,498
Consider just buying one. Any USB-type phone charger will work better than anything you build, and they can be found for very little money.
 

wayneh

Joined Sep 9, 2010
17,498
That'll work, and the input voltage can be from ~6-24V AC. However, the more voltage you drop across the 7805, the more heat it will produce and the bigger heat sink it will need.
 

thatoneguy

Joined Feb 19, 2009
6,359
Hi Zeeshan,

Here's a diagram on a pcb you can use for your 5v supply
That will dissipate (waste) 2 Watts as heat when the load is 500mA.

A switching power supply dissipates fractions of a watt of heat at 500mA load.

Plus, +5V 500mA to 2A are all over from cheap to free due to their use in phones, mp3 players, and many other consumer electronics. The designers often change the "end" for each model, so if you chop that off, you have an extremely stable power source, essentially for free.
 

soda

Joined Dec 7, 2008
177
That will dissipate (waste) 2 Watts as heat when the load is 500mA.

A switching power supply dissipates fractions of a watt of heat at 500mA load.

This guy wanted to build a project. if he use a ready made smp it wont be what he asked for as far as i concern. So, he can just add a heat-sink to the regulator. Change the 9vac input to a 6vac transformer.
 

wayneh

Joined Sep 9, 2010
17,498
This guy wanted to build a project. if he use a ready made smp it wont be what he asked for as far as i concern
That's a valid position. However I'm personally thankful that when I come here with preconceived notions of what I want, the smart people here challenge those notions and remind me of much simpler solutions, if those exist. That's what friends are for, to challenge us before we do something silly. The OP could very easily find a circuit for himself if all he wants is a circuit. Engaging with the living, breathing people here implies a need for a bit more, the wisdom of one's friends.
 

soda

Joined Dec 7, 2008
177
That's a valid position. However I'm personally thankful that when I come here with preconceived notions of what I want, the smart people here challenge those notions and remind me of much simpler solutions, if those exist. That's what friends are for, to challenge us before we do something silly. The OP could very easily find a circuit for himself if all he wants is a circuit. Engaging with the living, breathing people here implies a need for a bit more, the wisdom of one's friends.
Hey wayneh, thanks for the lecture you just gave me. I'LL remind myself of it the next time i post a reply.
 
Top