Switching a video signal with a relay
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Posts: 46,084
If there are only a momentary roll in the image when it switch this is
normal since sources are not "genlocked" - running with sync in phase.
Any low power relay should work. Check if noise is coming from
your power supply or regulator.
ACJaqcques
charlieb83@h... wrote:
>
> Hi all. My project consists of an infrared module hooked up to a pin
> on a bs2. When the bs2 recieves the proper signal from a remote
> control it switches a relay connected to another pin of the stamp.
> This works with no problem. The problem is that the relay is
> switching a video signal--I want to be able to switch between 2 video
> sources (I'm using just standard rG6 cable with f-connectors.) Every
> time I power up the circuit, the picture on the tv becomes fuzzy.(I
> assume the interference is coming from the relay) Is there anything
> I can do to get rid of this interference? Should I be using a
> certain kind of relay to swith a video signal?
>
> Thanks,
>
> Charlie
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
normal since sources are not "genlocked" - running with sync in phase.
Any low power relay should work. Check if noise is coming from
your power supply or regulator.
ACJaqcques
charlieb83@h... wrote:
>
> Hi all. My project consists of an infrared module hooked up to a pin
> on a bs2. When the bs2 recieves the proper signal from a remote
> control it switches a relay connected to another pin of the stamp.
> This works with no problem. The problem is that the relay is
> switching a video signal--I want to be able to switch between 2 video
> sources (I'm using just standard rG6 cable with f-connectors.) Every
> time I power up the circuit, the picture on the tv becomes fuzzy.(I
> assume the interference is coming from the relay) Is there anything
> I can do to get rid of this interference? Should I be using a
> certain kind of relay to swith a video signal?
>
> Thanks,
>
> Charlie
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
Comments
cables and or the power supply itself.
ACJacques
charlieb83@h... wrote:
>
> If the noise is coming from my power source, what's the best way to
> rid of this?
>
> --- In basicstamps@y..., AC Jacques <acjacques@i...> wrote:
> > If there are only a momentary roll in the image when it switch this
> is
> > normal since sources are not "genlocked" - running with sync in
> phase.
> > Any low power relay should work. Check if noise is coming from
> > your power supply or regulator.
> > ACJaqcques
> >
> > charlieb83@h... wrote:
> > >
> > > Hi all. My project consists of an infrared module hooked up to a
> pin
> > > on a bs2. When the bs2 recieves the proper signal from a remote
> > > control it switches a relay connected to another pin of the stamp.
> > > This works with no problem. The problem is that the relay is
> > > switching a video signal--I want to be able to switch between 2
> video
> > > sources (I'm using just standard rG6 cable with f-connectors.)
> Every
> > > time I power up the circuit, the picture on the tv becomes fuzzy.
> (I
> > > assume the interference is coming from the relay) Is there
> anything
> > > I can do to get rid of this interference? Should I be using a
> > > certain kind of relay to swith a video signal?
> > >
> > > Thanks,
> > >
> > > Charlie
> > >
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
on a bs2. When the bs2 recieves the proper signal from a remote
control it switches a relay connected to another pin of the stamp.
This works with no problem. The problem is that the relay is
switching a video signal--I want to be able to switch between 2 video
sources (I'm using just standard rG6 cable with f-connectors.) Every
time I power up the circuit, the picture on the tv becomes fuzzy.(I
assume the interference is coming from the relay) Is there anything
I can do to get rid of this interference? Should I be using a
certain kind of relay to swith a video signal?
Thanks,
Charlie
rid of this?
--- In basicstamps@y..., AC Jacques <acjacques@i...> wrote:
> If there are only a momentary roll in the image when it switch this
is
> normal since sources are not "genlocked" - running with sync in
phase.
> Any low power relay should work. Check if noise is coming from
> your power supply or regulator.
> ACJaqcques
>
> charlieb83@h... wrote:
> >
> > Hi all. My project consists of an infrared module hooked up to a
pin
> > on a bs2. When the bs2 recieves the proper signal from a remote
> > control it switches a relay connected to another pin of the stamp.
> > This works with no problem. The problem is that the relay is
> > switching a video signal--I want to be able to switch between 2
video
> > sources (I'm using just standard rG6 cable with f-connectors.)
Every
> > time I power up the circuit, the picture on the tv becomes fuzzy.
(I
> > assume the interference is coming from the relay) Is there
anything
> > I can do to get rid of this interference? Should I be using a
> > certain kind of relay to swith a video signal?
> >
> > Thanks,
> >
> > Charlie
> >
> >
> >
> > Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
leads are as short as possible. You may even want to add a large (10uF) and
a small (0.01uF) capacitor to the leads. If the noise continues, than the
source of your problems is most likely not the power source.
Phil
Original Message
From: <charlieb83@h...>
To: <basicstamps@yahoogroups.com>
Sent: Thursday, March 29, 2001 5:49 PM
Subject: [noparse][[/noparse]basicstamps] Re: Switching a video signal with a relay
> If the noise is coming from my power source, what's the best way to
> rid of this?
>
>
>
>
> --- In basicstamps@y..., AC Jacques <acjacques@i...> wrote:
> > If there are only a momentary roll in the image when it switch this
> is
> > normal since sources are not "genlocked" - running with sync in
> phase.
> > Any low power relay should work. Check if noise is coming from
> > your power supply or regulator.
> > ACJaqcques
> >
> > charlieb83@h... wrote:
> > >
> > > Hi all. My project consists of an infrared module hooked up to a
> pin
> > > on a bs2. When the bs2 recieves the proper signal from a remote
> > > control it switches a relay connected to another pin of the stamp.
> > > This works with no problem. The problem is that the relay is
> > > switching a video signal--I want to be able to switch between 2
> video
> > > sources (I'm using just standard rG6 cable with f-connectors.)
> Every
> > > time I power up the circuit, the picture on the tv becomes fuzzy.
> (I
> > > assume the interference is coming from the relay) Is there
> anything
> > > I can do to get rid of this interference? Should I be using a
> > > certain kind of relay to swith a video signal?
> > >
> > > Thanks,
> > >
> > > Charlie
> > >
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
>
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>
>
You didn't clarify whether you're switching RF or baseband video, but I'll
assume it's RF because of the connectors you're using and the reference to
a TV set.
Anyway, if you find that the interference is generally less when you tune
the TV to higher channels, then it's most likely that your Stamp is
radiating RF interference (RFI). The master clock oscillator is usually at
fault here, but any exposed wiring that carries rapidly changing digital
signals can cause similar symptoms.
The cure is to isolate your digital control system from the RF switching
section. If most of the RFI is entering the TV via exposed antenna wiring
at the relay, then you should be able to fix it by mounting the relay in a
shielded (metal) enclosure and filtering the coil connections with
feedthrough capacitors. Female F fittings are designed to be mounted in
metal panels, and maintain full shielding when used in this way.
Special RF relays (or switching diodes) are normally used for applications
like this, because general-purpose relays often have excessive capacitive
coupling between the open contacts at TV broadcast frequencies. In some
cases, high-isolation relays are an FCC legal requirement. Your TV antenna
could very efficiently broadcast RF leakage from a video game, ferinstance...
>Hi all. My project consists of an infrared module hooked up to a pin
>on a bs2. When the bs2 recieves the proper signal from a remote
>control it switches a relay connected to another pin of the stamp.
>This works with no problem. The problem is that the relay is
>switching a video signal--I want to be able to switch between 2 video
>sources (I'm using just standard rG6 cable with f-connectors.) Every
>time I power up the circuit, the picture on the tv becomes fuzzy.(I
>assume the interference is coming from the relay) Is there anything
>I can do to get rid of this interference? Should I be using a
>certain kind of relay to swith a video signal?
Mike Hardwick, for Decade Engineering -- <http://www.decadenet.com>
Manufacturer of the famous BOB-II Serial Video Text Display Module!
To: basicstamps@yahoogroups.com
Date: Fri, 30 Mar 2001 01:16:11 -0000
>This works with no problem. The problem is that the relay is
>switching a video signal--I want to be able to switch between 2 video
>sources (I'm using just standard rG6 cable with f-connectors.) Every
>time I power up the circuit, the picture on the tv becomes fuzzy.(I
>assume the interference is coming from the relay) Is there anything
Try connecting your video in and out wires together as if they had been
switched by your relay. Powering up and activating your switcher should
result in no change to the signal if the relay is suspect, otherwise you
might have other problems such as lack of shielding on the video cables
etc.
If it proves to be the relay, then perhaps it's not suitable for use at
video frequencies and you should look at video crosspoint switches like
those made by Maxim.
--
Regards,
Derryck Croker