[TriEmbed] Driving 32 5v relays

[Richard Prevette]

Thanks all for the comments.  Very informative.  Rodney, I wish I'd seen
this board before I started but if had to buy more boards, I would look at
solid state.  (I am using 4 8 channel boards.)

I found a 5v 3a wall adapter on Amazon $12.00.  Looks like that will do the
job.

On Thu, Jul 16, 2015 at 10:33 AM, Richard Prevette <
prevette.richard at gmail.com> wrote:

> The answer the first comment is mostly money.  I am using c9 size
> Christmas lights for a yard display.  I have 16 PVC pips painted like candy
> canes with two lights per pole.
>
> The second comment looks like just the ticket but would it have to be
> wired to car battery or a 12v wall adapter with at least
> a 3 amp rating?
>
> On Thu, Jul 16, 2015 at 10:16 AM, Adam Haile <email at adamhaile.net> wrote:
>
>> Stupid question... why not just use digital LEDs?
>> https://www.youtube.com/watch?v=_nbuSgYoCSQ
>> Full disclaimer: I have a tiny business that does LED lighting stuff, but
>> I am also just a huge fan of digital LED strips since they take away
>> complications like those with relays and such.
>>
>> More on your original question... no, no... not a resistor to do 14v ->
>> 5v! You would be dropping 9v and @ 3A be dissipating 27W!   I have bins
>> full of buck converters like the one linked below that will do 8-23V input
>> and output a nice steady 5V. They work great and are very efficient.
>>
>>
>> http://www.amazon.com/Nextrox%C2%AE-Display-Supply-Converter-Module/dp/B00CBCGAL8/
>>
>> On Thu, Jul 16, 2015 at 11:10 AM, Richard Prevette via TriEmbed <
>> triembed at triembed.org> wrote:
>>
>>> I am making a Christmas light display using 32 relays.  Using arduino
>>> and four 74HC595n shift registers.
>>> The relays are SRD-5vDC-SL-C.  Here is the question: I may be
>>> misunderstanding but the datasheet states each
>>> relay takes 72ma.  I put  a meter across the power and that seems
>>> right.  At one point all relays will be on at the same time.
>>> That looks like I need a power source that will supply about 2.3 amps.
>>> 32 x 72 x 1000 = 2.3a (Correct ?)
>>>
>>> I have a Dell AC adapter that states output at 14v dc and 3 amps.  All I
>>> need is a resister to lower 14 to 5 volts and
>>> I good to go?
>>>
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>>
>
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