buzzing relays....what makes a relay buzz?
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From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
buzzing relays....what makes a relay buzz?
what makes a normal SPST 12volt relay buzz when its not "turned on" ?
i have this hooked up to the torque converter lock out and an MSD RPM activated switch, but the question is the same why is the relay buzzing before it gets switched on?
heres the link to what i have done...
http://forums.corvetteforum.com/show...996&forum_id=3
i have this hooked up to the torque converter lock out and an MSD RPM activated switch, but the question is the same why is the relay buzzing before it gets switched on?
heres the link to what i have done...
http://forums.corvetteforum.com/show...996&forum_id=3
Last edited by bobs77vet; Jun 6, 2005 at 10:18 PM.
Drifting
Joined: Mar 2003
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From: Canberra AUSTRALIA
St. Jude Donor '05-'06
Originally Posted by bobs77vet
what makes a normal SPST 12volt relay buzz when its not "turned on" ?
i have this hooked up to the torque converter lock out and an MSD RPM activated switch, but the question is the same why is the relay buzzing before it gets switched on?
heres the link to what i have done...
http://forums.corvetteforum.com/show...996&forum_id=3
i have this hooked up to the torque converter lock out and an MSD RPM activated switch, but the question is the same why is the relay buzzing before it gets switched on?
heres the link to what i have done...
http://forums.corvetteforum.com/show...996&forum_id=3
Bob,
Its possible you have some voltage on the relay that is causing it to buzz. A solenoid is a magnetic switch. Apply power and the magnet activates pulling on a plunger and activating the switch.
Consider a buzzer, it is similar in design, apply power, activate magnet, pull plunger, movement de-activates switch (probably due to the current flow), and the cycle repeats.
In your solenoid you probably have 1-2 volts sitting on it that is causing it to almost activate. On your thread you mentioned an MSD. Distributors and anything high voltage generates a lot of electrical noise. Try putting a filter (capacitor) near the input of the solenoid, may help with the electrical noise you seem to have. The filter will ground out any electrical noise you have.
Try putting a digital multimeter on there and you may see the voltage flutter around. You may need an oscilliscope but I doubt you have one of those in the garage (neither do I)
Cheers,
Pete
Burning Brakes
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From: Olive Branch MS
St. Jude Contributor
Originally Posted by stingry
Bob,
Its possible you have some voltage on the relay that is causing it to buzz.
Its possible you have some voltage on the relay that is causing it to buzz.
In the many years I have worked as an Industrial Electrician I have seen this many times. A small amount of voltage to a relay will make it buzz or hum and even chatter if enough is present.
Thread Starter
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From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
Originally Posted by stingry
Bob, Its possible you have some voltage on the relay that is causing it to buzz. A solenoid is a magnetic switch. Apply power and the magnet activates pulling on a plunger and activating the switch.
In your solenoid you probably have 1-2 volts sitting on it that is causing it to almost activate.
Pete
In your solenoid you probably have 1-2 volts sitting on it that is causing it to almost activate.
Pete
Originally Posted by brooksman9
In the many years I have worked as an Industrial Electrician I have seen this many times. A small amount of voltage to a relay will make it buzz or hum and even chatter if enough is present.i know i have voltage sitting in the relay with an "open ground", the MSD RPM actuated switch is controlling the ground circuit to the relay....and the ground circuit is open when the relay is buzzing and at the selected RPM the ground circuit is completeted and the relay allows power to go to the torque converter lock up and the buzzing stops....i wonder if i have a "technically bad design" by controlling the ground circuit of a relay....the design was mine , based on what sounded like a good idea at the time....
Last edited by bobs77vet; Jun 7, 2005 at 08:49 AM.
Drifting
Joined: Mar 2003
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From: Canberra AUSTRALIA
St. Jude Donor '05-'06
Bob,
Try this. Run a temp wire to your battery negative and connect it to the ground wire going to your relay. See if that eliminates the buzz. If it does you have a grounding problem. Go to all the ground connection points and clean the terminals. Get a smear (a tiny tiny bit) of conductve copper paste and put it on the connections before you re-connect them.
Test how good your grounds are by putting an ohmeter between each point and and the -ve terminal that connects to your battery. Disconnect the -ve terminal from the battery first. You should see a reading less then 5 Ohms. If it more then you have a ground problem. Start hunting.
Good luck.
Pete
Try this. Run a temp wire to your battery negative and connect it to the ground wire going to your relay. See if that eliminates the buzz. If it does you have a grounding problem. Go to all the ground connection points and clean the terminals. Get a smear (a tiny tiny bit) of conductve copper paste and put it on the connections before you re-connect them.
Test how good your grounds are by putting an ohmeter between each point and and the -ve terminal that connects to your battery. Disconnect the -ve terminal from the battery first. You should see a reading less then 5 Ohms. If it more then you have a ground problem. Start hunting.
Good luck.
Pete
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From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
Originally Posted by stingry
Bob,
Try this. Run a temp wire to your battery negative and connect it to the ground wire going to your relay. See if that eliminates the buzz. If it does you have a grounding problem. Go to all the ground connection points and clean the terminals. Get a smear (a tiny tiny bit) of conductve copper paste and put it on the connections before you re-connect them.
Test how good your grounds are by putting an ohmeter between each point and and the -ve terminal that connects to your battery. Disconnect the -ve terminal from the battery first. You should see a reading less then 5 Ohms. If it more then you have a ground problem. Start hunting.
Good luck.
Pete
Try this. Run a temp wire to your battery negative and connect it to the ground wire going to your relay. See if that eliminates the buzz. If it does you have a grounding problem. Go to all the ground connection points and clean the terminals. Get a smear (a tiny tiny bit) of conductve copper paste and put it on the connections before you re-connect them.
Test how good your grounds are by putting an ohmeter between each point and and the -ve terminal that connects to your battery. Disconnect the -ve terminal from the battery first. You should see a reading less then 5 Ohms. If it more then you have a ground problem. Start hunting.
Good luck.
Pete
i know that running a ground to the relay will fix the problem....that is the same as when my MSD RPM switch is activated and it completes the ground circuit...all the buzzing stops....so i guess the question is can i use a relay if i need to use the relays ground as the switching mechanism? or do i need a special type of relay?
C6 the C5 of tomorrow
Joined: Nov 2000
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From: Twin Cities Minnesota
sounds to me like the MSD line isn't completely opening up and is letting just enough current through to almost activate the relay.
One trick may be to put a diode in series with the relay, The extra .7 volt drop may eliminate the chatter...
One trick may be to put a diode in series with the relay, The extra .7 volt drop may eliminate the chatter...
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From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
Originally Posted by 427V8
sounds to me like the MSD line isn't completely opening up and is letting just enough current through to almost activate the relay.
One trick may be to put a diode in series with the relay, The extra .7 volt drop may eliminate the chatter...
One trick may be to put a diode in series with the relay, The extra .7 volt drop may eliminate the chatter...
Originally Posted by BB wowbagger
I`m using a MSD RPM switch to my shiftlight and that darn thing leaks voltage.
You can see my LEDs glowing when it starts to get darker outside..
You can see my LEDs glowing when it starts to get darker outside..
interesting thoughts, i think you are on to something......so the MSD switch is leaking a small amount of current to ground .... which is making my relay act like a buzzer and it keeps "cycling"....and then when it finally closes all is good.... that sounds like the likely culprit....how do i fix it?
tell me more about the diode type, specs, radio shack part number , i don't know much/anything about diodes...i appreciate the help, thks bob
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From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
Originally Posted by bobs77vet
interesting thoughts, i think you are on to something......so the MSD switch is leaking a small amount of current to ground .... which is making my relay act like a buzzer and it keeps "cycling"....and then when it finally closes all is good.... that sounds like the likely culprit....how do i fix it?
tell me more about the diode type, specs, radio shack part number , i don't know much/anything about diodes...i appreciate the help, thks bob
tell me more about the diode type, specs, radio shack part number , i don't know much/anything about diodes...i appreciate the help, thks bob
i would like to try the diode or perhaps something else to try and fix this any thoughts?
C6 the C5 of tomorrow
Joined: Nov 2000
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From: Twin Cities Minnesota
The idea of using a diode in series with the relay is that a diode has a constant voltage drop in one direction of about .7 volts. A resistors voltage drop depends upon current flow so it has less drop when you want more and more drop when you want less...
A diode is an electrical valve. it lets current flow in one direction. Like all valves there is some resistance to flow, thats where you get that .7v.
if you need to take just a little voltage out of a circuit 1 or 2 diodes can do that.
like this, Pos wire---Relay---diode--MSD
The diode has to be in the circuit the correct direction or nothing will work.
There is a stripe on the diode that tells you which way to hook it up.
the stripe goes towards the MSD or ground.
If 1 diode helps but doesn't make it go away try two in series.
As far as type, use a 1 amp rectifier from radio shack.
A diode is an electrical valve. it lets current flow in one direction. Like all valves there is some resistance to flow, thats where you get that .7v.
if you need to take just a little voltage out of a circuit 1 or 2 diodes can do that.
like this, Pos wire---Relay---diode--MSD
The diode has to be in the circuit the correct direction or nothing will work.
There is a stripe on the diode that tells you which way to hook it up.
the stripe goes towards the MSD or ground.
If 1 diode helps but doesn't make it go away try two in series.
As far as type, use a 1 amp rectifier from radio shack.
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From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
Originally Posted by 427V8
like this, Pos wire---Relay---diode--MSD
The diode has to be in the circuit the correct direction or nothing will work.
There is a stripe on the diode that tells you which way to hook it up.
the stripe goes towards the MSD or ground.
If 1 diode helps but doesn't make it go away try two in series.
As far as type, use a 1 amp rectifier from radio shack.
The diode has to be in the circuit the correct direction or nothing will work.
There is a stripe on the diode that tells you which way to hook it up.
the stripe goes towards the MSD or ground.
If 1 diode helps but doesn't make it go away try two in series.
As far as type, use a 1 amp rectifier from radio shack.
oh by the way my last car was a 1960 3000 bt7
C6 the C5 of tomorrow
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From: Twin Cities Minnesota
Originally Posted by bobs77vet
thanks i will get this at lunch time in a few minutes...i will be putting this in tonight, thanks for the help, i will let you know how it works.
oh by the way my last car was a 1960 3000 bt7
oh by the way my last car was a 1960 3000 bt7
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From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
Originally Posted by Lovin_my_81
I have a relay under the center console in my 81 that has the same problem. it is buzzing when I slow down to idle. does anyone know what the relay is for?
Originally Posted by 427V8
Well now I jut hope it works!
i am now the owner of a package of 25 assorted 1 amp diodes...more then i will ever need...which plan is better
1. to solder them to wire which is connected to crimped spade terminals and cover the diode with heat shrink tubing, or
2. solder it to spade terminals and cover it with heat shrink tubing?
thks bob
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From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
well installed two diodes and it made no difference....got out my ac/dc multimeter tester put it in series and measured "36m" for current needed to make it "buzz". what do i do now?
what is 36m ? is that 36milliamps or .036 amps? if so what do i need to overcome this? that does not seem like a lot of current.
what do you think? thanks bob
what is 36m ? is that 36milliamps or .036 amps? if so what do i need to overcome this? that does not seem like a lot of current.
what do you think? thanks bob
Last edited by bobs77vet; Jun 7, 2005 at 09:34 PM.
Thread Starter
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From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
Originally Posted by bobs77vet
well installed two diodes and it made no difference....got out my ac/dc multimeter tester put it in series and measured "36m" for current needed to make it "buzz". what do i do now?
what is 36m ? is that 36milliamps or .036 amps? if so what do i need to overcome this? that does not seem like a lot of current.
what do you think? thanks bob
what is 36m ? is that 36milliamps or .036 amps? if so what do i need to overcome this? that does not seem like a lot of current.
what do you think? thanks bob
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From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
well heres a $26 relay....yikes, perhaps its wound a little tighter to stop the chatter
http://www.jegs.com/cgi-bin/ncommerc...69&prmenbr=361
http://www.jegs.com/cgi-bin/ncommerc...69&prmenbr=361
Racer
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From: Eagle WI
Bob, don't buy the $26 relay, I think I've got a solution (simple). Have to go to a meeting in 5 min. I'll think about it more over lunch and post something later this afternoon if you don't get it by then.
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From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
Originally Posted by Todd68
Bob, don't buy the $26 relay, I think I've got a solution (simple). Have to go to a meeting in 5 min. I'll think about it more over lunch and post something later this afternoon if you don't get it by then.
thanks Todd i appreciate your help and eveyone elses. bob