Author Topic: Where to purchase a power supply  (Read 1527 times)

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Offline T-ElectronicsTopic starter

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Where to purchase a power supply
« on: October 06, 2017, 11:47:25 pm »
I am working on a device that uses a raspberry pi (5v and 2.5 amps) and a brushless dc motor (11.1V at .066 amps -- http://1012007.kancart.com/item_description/431). I want the device to plug directly into the wall.  I think the best way to achieve this would be to use 2 separate power supplies, one that powers the raspberry pi, and a separate 12 V, 500 to 2000 mA mains power supply for the motor.  My question now is where to I go to find a power supply?  I only need to purchase a couple for the first prototype.  What websites or other places do people use to purchase their power supplies?
 

Offline tautech

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Re: Where to purchase a power supply
« Reply #1 on: October 07, 2017, 07:46:48 pm »
I am working on a device that uses a raspberry pi (5v and 2.5 amps) and a brushless dc motor (11.1V at .066 amps -- http://1012007.kancart.com/item_description/431). I want the device to plug directly into the wall.  I think the best way to achieve this would be to use 2 separate power supplies, one that powers the raspberry pi, and a separate 12 V, 500 to 2000 mA mains power supply for the motor.  My question now is where to I go to find a power supply?  I only need to purchase a couple for the first prototype.  What websites or other places do people use to purchase their power supplies?
Welcome to the forum.

Sounds like you need a bench PSU with multiple channels, the # of channels wanted/needed being the decision you must make to best suit your projects.
You might also consider how good the display is for giving you load and settings info and if the PSU is capable of series mode and parallel mode to supply higher voltages or higher currents.
As you're in the US have a look at Saelig's offerings:
http://www.saelig.com/

As a member here now you can ask for a discount code in this thread:
https://www.eevblog.com/forum/testgear/equipment-discounts-from-saelig/
Avid Rabid Hobbyist
Siglent Youtube channel: https://www.youtube.com/@SiglentVideo/videos
 

Offline edavid

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Re: Where to purchase a power supply
« Reply #2 on: October 07, 2017, 08:46:28 pm »
I am working on a device that uses a raspberry pi (5v and 2.5 amps) and a brushless dc motor (11.1V at .066 amps -- http://1012007.kancart.com/item_description/431). I want the device to plug directly into the wall.  I think the best way to achieve this would be to use 2 separate power supplies, one that powers the raspberry pi, and a separate 12 V, 500 to 2000 mA mains power supply for the motor.  My question now is where to I go to find a power supply?  I only need to purchase a couple for the first prototype.  What websites or other places do people use to purchase their power supplies?

1. A Raspberry Pi doesn't use 2.5A unless you have full loads on all the USB ports.  Most people just run them from a cell phone charger.

2. On the other hand, your motor has a "Max Current" rating of 10A.  How are you planning to drive it?


Sounds like you need a bench PSU with multiple channels, the # of channels wanted/needed being the decision you must make to best suit your projects.

His project needs 2 fixed voltages, why would he need or want a bench supply?
« Last Edit: October 07, 2017, 08:48:04 pm by edavid »
 

Offline KL27x

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Re: Where to purchase a power supply
« Reply #3 on: October 07, 2017, 09:53:28 pm »
For small lots and oneoffs in the US, I would check Marlin P Jones Associates (MPJA.com) out of florida. One of their specialties seems to be liquidating NOS electronics stuff (Much of which I assume is no longer in production). They are particularly useful (to me) for power supplies.

If you need a guaranteed supply (of power supplies), then you may have to ask. They have some more expensive PSU's which may be in production. But the really cheap walwarts and whatnot appear to be closeouts. Whatever is for sale today could be gone tomorrow.

It's not unusual to find power supplies like what you're asking about for 4-5.00. But shipping is usually 9 or 10.00, minimum. So take a moment to browse and maybe buy a couple extra psu or other items.
« Last Edit: October 07, 2017, 10:06:41 pm by KL27x »
 


Offline KL27x

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Re: Where to purchase a power supply
« Reply #5 on: October 07, 2017, 10:09:28 pm »
http://www.mpja.com/5-Volt-Plug-Power-Adapter-2A-Leader-Used/productinfo/31484+PS/

http://www.mpja.com/12-Volt-Adapter-Power-Supply-125A-Delta-USED/productinfo/31825+PS/

I have a big ole box of PSU's, transformers, and switchers. But if I don't have X or Y, MPJA has it covered. They are like a hoarder gone commercial.
« Last Edit: October 07, 2017, 10:12:14 pm by KL27x »
 

Offline james_s

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Re: Where to purchase a power supply
« Reply #6 on: October 17, 2017, 07:52:56 pm »
Is there a decent thrift store around you? It's not unusual to find a bin of orphaned "wall wart" type power supplies for a buck or two each. 5V and 12V are both very common voltages and it's not hard to find them in the range of 1-2A. If you're anything like me, you might already have a box of them leftover from junked equipment.
 


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