[TriEmbed] Circuit Help

Mauricio Tavares raubvogel at gmail.com
Fri Dec 4 12:59:52 CST 2015


On Fri, Dec 4, 2015 at 1:38 PM, Rodney Radford via TriEmbed
<triembed at triembed.org> wrote:
> Careful using two SPDT relays to emulate a DPDT - if the one relay activates
> a little faster than the other you could result in a direct short (one still
> open and the other closed, or vice versa).  You could do this with two RPi
> pins and make sure (in software) that only one is activated at a time.
>
      Bosch has been putting out a nice DPDT relay since Tutankhamun
"borrowed" the family car to get wasted and laid. You provide the
voltage on pin 30, signal on 86, ground on 85. voltage from 30 goes to
87a when relay is off and 87 when it is on. You can find those relays
in your friendly junkyard on Volvos, Saabs, Mercedes, and BMWs to
quote a few cars.

>
> On Fri, Dec 4, 2015 at 1:13 PM, Josh Wyatt via TriEmbed
> <triembed at triembed.org> wrote:
>>
>> To further Pete's suggestion- you can use a single DPDT or two SPDT relays
>> to accomplish this.
>>
>> Here's a nice allaboutcircuits.com post about it:
>>
>> http://forum.allaboutcircuits.com/threads/reversing-polarity-with-spdt-relays.30679/
>>
>> Let me know if you need more help!
>>
>> Thanks,
>> Josh
>>
>> On Fri, Dec 4, 2015 at 1:07 PM, Pete Soper via TriEmbed
>> <triembed at triembed.org> wrote:
>>>
>>> Just string together a few plain relays.
>>> -Pete
>>>
>>>
>>> On 12/04/2015 12:51 PM, Grawburg via TriEmbed wrote:
>>>>
>>>> I have a quarter-turn ball valve with a 12V actuator [HSH-Flo 1/2" DN15
>>>> 12VDC CR-05 FNPT SS304 Position Feedback Motorized Electric Ball Valve.]
>>>> I'm using opto-isolated relay activated by a Raspberry Pi but can only
>>>> control one direction because the valve reverses direction by flipping the
>>>> leads. If I was doing it mechanically I would have a double pole triple
>>>> throw rotary switch. I cannot find a suitable opto-isolated relay that is
>>>> 2P3T...at least one that doesn't cost a fortune. Any suggestions to help me
>>>> think this through would be welcomed.
>>>>
>>>>
>>>> Thanks,
>>>> Brian Grawburg
>>>>
>>>>
>>>>
>>>>
>>>>
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>>>
>>>
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>>
>>
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>
>
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