DC motor control w/ Solid State Relays
Archiver
Posts: 46,084
Colleagues,
I need to run a 12VDC 25A(peak) motor in both directions, so I'm
building an H-bridge. Currently I'm looking for affordable Solid
State Relays (SSR) to make an H-bridge. Unfortunately most SSRs are
made for AC. Can you suggest a cheap source of DC SSRs? (Preferrably
small. Preferrably SPDT. Even more preferrably packaged SSR H-
bridges.)
Thanks,
Nick
I need to run a 12VDC 25A(peak) motor in both directions, so I'm
building an H-bridge. Currently I'm looking for affordable Solid
State Relays (SSR) to make an H-bridge. Unfortunately most SSRs are
made for AC. Can you suggest a cheap source of DC SSRs? (Preferrably
small. Preferrably SPDT. Even more preferrably packaged SSR H-
bridges.)
Thanks,
Nick
Comments
wrote:
> Colleagues,
>
> I need to run a 12VDC 25A(peak) motor in both directions, so I'm
> building an H-bridge. Currently I'm looking for affordable Solid
> State Relays (SSR) to make an H-bridge. Unfortunately most SSRs are
> made for AC. Can you suggest a cheap source of DC SSRs?
(Preferrably
> small. Preferrably SPDT. Even more preferrably packaged SSR H-
> bridges.)
>
> Thanks,
> Nick
Hi Nick,
the solid state relay is a mildly intracate device made up of a
darlington and a triac some caps and resistors and such.
if all you want is to switch a 25 amp load, considder a MOSFET. you
can use two to double the rating. This should offer a simple
solution.
But check Digi-Key for SSR's
http://rocky.digikey.com/WebLib/Crydom/Web%20Data/1-DC%20Series%20
(D1D,%20D2D,%20D4D,%20D5D).pdf
or CC1039-ND @ $62.64 each in lots of 10 parts.
Dave
they have a EDE16020 20 amp H-Bridge DC motor controller that appears to do
what your looking for.
as a cheaper alternative, I agree like Dave said MOSFETs would be a good
choice if you don't mind hacking out circuit. To operate a motor in both
direction you will need 2 P-channel and 2 N-channel or 4 of each if you
chose to parallel them. a quick google search landed this circuit
http://www.armory.com/~rstevew/Public/Motors/H-Bridges/Blanchard/h-bridge.htm
as a side note, I have several dozen of Opto 22 25 amp SSR that I'll be
willing to part with. They work fine for DC as in solar panel to battery
cut-off switch.
Hey, I have a question. Even tho SSR are designed to work with AC, is there
anything wrong with using DC with them?
Daryl
At 01:41 PM 6/14/2004, you wrote:
>Colleagues,
>
>I need to run a 12VDC 25A(peak) motor in both directions, so I'm
>building an H-bridge. Currently I'm looking for affordable Solid
>State Relays (SSR) to make an H-bridge. Unfortunately most SSRs are
>made for AC. Can you suggest a cheap source of DC SSRs? (Preferrably
>small. Preferrably SPDT. Even more preferrably packaged SSR H-
>bridges.)
>
>Thanks,
>Nick
>
>
>
>
>To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
>from the same email address that you subscribed. Text in the Subject and
>Body of the message will be ignored.
>
>Yahoo! Groups Links
>
>
>
>
[noparse][[/noparse]Non-text portions of this message have been removed]
is there anything wrong with using DC with them?
>
> Daryl
Yes, there is. AC SSRs turn off when the command signal goes to zer0
and the AC sinusoid crosses zer0. DC voltage doesn't cross zer0, so
you can turn on the DC voltage with an AC SSR, but you can't turn it
off.
Nick
(and are used like) AC SSR's, but control DC voltage outputs. They are
quite pricey! Have a look at:
http://www.electronicsurplus.com/commerce/catalog/product.jsp?product_id=72467
But for H-bridge DC motor control, I don't know why you wouldn't just use
power mosfets?
Steve
///////////////////////////////
> > Hey, I have a question. Even tho SSR are designed to work with AC,
>is there anything wrong with using DC with them?
> >
> > Daryl
>
>Yes, there is. AC SSRs turn off when the command signal goes to zer0
>and the AC sinusoid crosses zer0. DC voltage doesn't cross zer0, so
>you can turn on the DC voltage with an AC SSR, but you can't turn it
>off.
>
>Nick