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Power Supply for QuickStart — Parallax Forums

Power Supply for QuickStart

blittledblittled Posts: 681
edited 2012-08-29 11:44 in Propeller 1
I was looking into powering a QuickStart through a USB charger rather than the computer. I found one at Radio Shack that has 2 outputs http://www.radioshack.com/product/index.jsp?productId=4439416#tabsetBasic . One is 5 V 500mA and the other is 5V 1 Amp. Would this work?

Comments

  • Mike GreenMike Green Posts: 23,101
    edited 2012-08-28 12:23
    Yes, either one of those should work although you have to jumper the /USB_PWR_EN line to ground. Normally, when the USB to serial interface is enumerated by the attached PC, the 5V from the USB bus is connected to the 3.3V regulator. When there's no PC, this is turned off. Grounding /USB_PWR_EN turns it back on whether or not a PC is connected.
  • varnonvarnon Posts: 184
    edited 2012-08-28 15:56
    It should work.
    But I have to add that I have had terrible luck with enercell power supplies from Radio Shack. Current and voltage do not seem to be as close to the intended values as other supplies. I had one 5v supply that started producing a mysterious buzz when more current was used, and another 12 v that just died spontaneously. I won't buy these anymore.

    Actually, I generally avoid Radio Shack all together. They don't even the right parts for their own equipment. Nobody in the store knows anything about electronics, and anytime I want to buy something a simple a single resistor I still have to wait forever because somebody is getting their cellphone set up.

    I think I am going to start recommending something like this to my friends.
    http://www.gadgetgangster.com/find-a-project/56.html?projectnum=408
    This way you only have one USB cable for power and programming. I think less cables will appeal to people.
  • blittledblittled Posts: 681
    edited 2012-08-28 19:39
    Thanks for the responses.
    @Mike I found out the add on board I'm using already has the /USB_PWR_EN grounded so that is no problem.
    @Varnon I have 2 300ma 3.5-12V and one 1 Amp 3.5V-12V Enercells and the only problem I had was I found they are not tightly regulated since I burned out a serial LCD in one week with one once since the ripple went beyond the LCD's max voltage input. If these 5V chargers are regulated I have no problem buying one.
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2012-08-28 19:48
    I've had excellent results with one of these:

    -Phil
  • RDL2004RDL2004 Posts: 2,554
    edited 2012-08-29 11:38
    You could also check at Walmart for cell phone chargers. I bought an ONN brand USB charger there a couple of weeks ago for less than $10. It has three interchangeable tips (mini USB, micro USB, Samsung) and is rated 800 mA. I ran a Raspberry Pi off on it for 5 days non-stop with no problems. I never checked it under load, but I did measure the output before using it at 5.18 volts with 1.5 mV of AC.
    ONN Charger.jpg
    1024 x 681 - 137K
  • Duane C. JohnsonDuane C. Johnson Posts: 955
    edited 2012-08-29 11:44
    These little switching wall worts are readily available at garage sales for $0.50 or $1.
    They are regulated at 5V with 1A currents on some.

    Duane J
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