开云体育

Dave

FYI, link to a GPIO pin electrical specifications document:

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Alan

On Sat, Aug 14, 2021 at 12:50 PM Dave / NR1DX <manuals@... <mailto:manuals@...>> wrote:

Alan

I just went out and traced/ measured the circuits

1) I stand corrected the 12V board uses 12V relays
2) On this board the T1/D1/R2 is a separate chip (array of 8) tied to
12V bus
3) the Optocouplers output side is tied to the 5V bus (from the
LM2576
chip) not the 12V Bus
4) The voltage at idle on "IN1" in your diagram is anywhere from 0
to 5V
depending on how long the pin is has been open? kind of a charge
build
up leakage thing I would guess thing (I guess?)
5) A voltage at IN1 anywhere between about 1.35V and 3.6 v will
fire the
optocoupler and thus the relay. Above or below these voltages no
relay
action
6) R1 is 1K, r2 is I think internal to chip darlington relay
driver...I
can send the chip number if your really interested

In general my impression is this board is "OK" to use with the
PI...your
thoughts?

If I had a good CAD/schematic program , I would finish reverse
engineering? and publish the schematic

Dave
NR1DX


On 8/14/2021 10:37 AM, Alan Blind, WA9WUD wrote:
> One word of caution.
>
> The 12v board you show is probably of the optical isolation type
> circuit. The "input" side is an optical diode, that when set to
> ground, via the GPIO pin, operates the other side of the
circuit, via
> a transistor, with its collector at 12v, where the 12v relay
coil resides.
>
> Be sure the "input" optical diode high side is no more than 5v.
? Any
> voltage greater than 5v, will "toast" the GPIO pin.
>
> Since your board references a 5v power supply, it looks like
that may
> be the case.
>
> Here is a "typical" relay diagram
>
> Relay.png
>
> Alan
>
> On Sat, Aug 14, 2021 at 9:59 AM Dave / NR1DX
<manuals@... <mailto:manuals@...>
> <mailto:manuals@...
<mailto:manuals@...>>> wrote:
>
>? ? ?Alan et all
>
>? ? ?That is a great find. and unlike many of the other relay
boards out
>? ? ?there, It has actual specs, documentation and a schematic.
>
>? ? ?A bit pricey but not bad. In the end I am going to need more
than 8
>? ? ?relays though. I looked and didn't find one by these guys. ,
but the
>? ? ?Amazooooo search engine was designed by a frustrated rat
>? ? ?psychologist.
>? ? ?They appear to be a real player in the new tech area (3D
printing)
>? ? ?, not
>? ? ?just another Great Wall Knock Off shop
>
>? ? ?I? am starting with this one recommended in an earlier
thread a few
>? ? ?months back
>
>

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>? ?
?<
<>>
>
>? ? ?But like many there is no real documentation that I could
find so
>? ? ?far .
>? ? ?It takes 12V DC and has a 5V output regulator which I am
guessing
>? ? ?could
>? ? ?be used to power the R-PI rather using the USB supply . My
remote
>? ? ?antenna switch uses 12V relays
>
>? ? ?Dave
>? ? ?NR1DX
>
>? ? ?On 8/14/2021 6:05 AM, Alan Blind, WA9WUD wrote:
>? ? ?> I call that the "plate of spaghetti" phase of the project.
>? ? ?>
>? ? ?> I found these boards were very helpful in cleaning up a
project.
>? ? ?> ?Combines a 12v to 5v power supply (RF clean), Raspberry Pi
>? ? ?mounting
>? ? ?> and eight GPIO built into the board and wired in, relays.
>? ? ?>
>? ? ?>
>

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>? ? ?>
>? ? ?> Alan. WA9WUD
>? ? ?>
>
>? ? ?--
>? ? ?Dave Manuals@... www.ArtekManuals.com
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>? ? ?< <>>
>
>? ? ?--
>? ? ?This email has been checked for viruses by Avast antivirus
software.
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Dave Manuals@... www.ArtekManuals.com
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