From your description, the bell is not a high powered bell. You say it's rated for 0.085 A current drain. That's not much. An 18V power supply, like any unregulated supply, typically provides a higher voltage under low load and this is less than 10% of full load (1.000 A). The voltage from your power supply is likely to be more like 20V or 22V at this load. I can't tell why it doesn't work, but this explanation is not something that makes sense.
What would you recommend me do? i tried moving the bell, didnt work. I want it to work but it makes no sence. It works with the buzzer and the only difference is i have a bell instead of a buzzer and they are connected to the same place, thats why i thoight it was power supplyu related cuz the buzzer has a WAY lower amp rating its like 15 mA. What would you recommend me do?
hey do u think the problem could be a short in the bell because of the wiring? i had to twist a bunch of extra wire to make it reach but some of the wire is crappy dollar store speaker wire. Coyld that be whats causing the system to reset?
You still haven't described how the Stamp itself is wired. Are you using a Parallax development board? What's the source of power for the Stamp?
Since the bell circuit is independent of the Stamp, a short there is likely to affect only the bell circuit. It could burn out the relay, but that's not likely to cause the Stamp to reset. A Stamp reset can be caused by noise getting into the Stamp's power supply or by an overload of the Stamp's power supply. Assuming that you now have diodes on both relay coils, that's a major source of noise that's now suppressed.
It would help if you posted some pictures of your board and the wiring coming off it. It would help if you posted a picture of your bell.
I am using Basic Stamp 2 on the board of education from the discovery kit.
I am also using a 9 volt dc 1 amp power supply to power the board of education and a 18 volt dc p[noparse][[/noparse]ower supply for the strobes and bell.
By the way i took out the diode temparary cuz it was not working rigt, it caused my bell to ring and then slowly die and turn off. I think i connected it wrong or it was not the right one. I cant see the diode causing it to reset since the buzzer works without it, howveer i willo figure the diode out and put it in to protect my basicm stamp.
Here is a picture of my bell and 2 of my board of education connected. Its the best shot if it i could get.
That at least eliminates the Stamp's power supply as a problem. The regulator on the Board of Education is robust, has a heatsink, and is fully capable of handling roughly 1A of +5V current.
I don't see the relays or the transistors driving them. You do need to fix the transistor circuit as I suggested. The diode needs to be connected in parallel with the relay coil with the cathode (bar) connected to the +5V end and the anode connected to the transistor end (using my circuit).
il fix the diode problem and the transisters are driving the relays. I was just unable to get it in the picture sorry. Anyways what else would u recommend after i tried all of your circuits like u recently said. Should i just screw the bell and get a horn strobe?
I really don't know. There's so much information you haven't provided even though you may think I've been pushing you for a lot.
For example, why is there a green wire lying next to (and seemingly contacting) the power plug to the Board of Education?
What relays are you using?
There are long wires coming off the Stamp pins for the relays and it's impossible to tell where the power wires (Vdd and Vss) associated with them run. These all can carry noise back into the Board of Education and potentially cause a reset. There are all kinds of ways to reduce this, anything from twisting pairs of wires together (usually a ground wire and another power or signal wire) to using shielded wire.
The green wire is for my VERY anoying buzzer i disconnected for obvious reasons. Itw asnt touching the power plug although it looked as it was, i checked and it was not. It cant be anything to do wth my wiring because the buzzer works on the relay. I will tell you that it does not reset if i program the bell to ring continuous, only when i program it to ring and off like i want. I am using 5 VDC 12 amp relays mounted into a PCB board soldered.
Like Mike said it still could be noise in your wiring since you have not taken any countermeasures.
firealarmfreak·said...
It cant be anything to do wth my wiring because the buzzer works on the relay.
The buzzers take a lot less current and create a lot less electrical noise. It still could be your wiring. Bring all the parts to your bench and hook it up with twisted/shielded wire and see what happens.
It is shiled wire. I truied the diode and it did not work any better. I wired it up like a schematic that someone sent me and his worked so it cvant be the wiring. Obviously its impossible to find the problem cuz i have fifty thousand people from other places besides the forum telling me what i should do and i dont know who to believe and to try all costs money so i dont care at this point.
Hey Sorry if i seemd a lttle mad in my last post. I am just frsuterated cuz i wanted it to work. I really appreciate your help.
I thiunk i may have the answer thoigh, could it possiblty be because i had to twsit a bunch of wire to make the bell reach to the basic stamp, and some of that is CRAPPY dollar store speaker wire? Cuiz it seemed betetr when i used less wire and had the bell beside the stamp without the dollar store wire.
I doubt that your problems have to do with "CRAPPY dollar store speaker wire". It might have to do with the length of the wire and the closeness of that wire to others attached to the Stamp. Based on the current drain you stated, pretty much any wire larger than 24 or 26 gauge will work for distances of a few feet. The effect of too small wire would be that the bell doesn't work well because too much voltage is lost in the resistance of the wire. This wouldn't cause the Stamp to reset.
Hey I connected my diode and it started smoking (although nothing was damaged) i disconnected the diode and everythings normal (no smoke and bell does not work right still). Can u make me a diagram and post it on how to connect my diode? The protective one between my relay and +5 volt.
Comments
Since the bell circuit is independent of the Stamp, a short there is likely to affect only the bell circuit. It could burn out the relay, but that's not likely to cause the Stamp to reset. A Stamp reset can be caused by noise getting into the Stamp's power supply or by an overload of the Stamp's power supply. Assuming that you now have diodes on both relay coils, that's a major source of noise that's now suppressed.
It would help if you posted some pictures of your board and the wiring coming off it. It would help if you posted a picture of your bell.
The more information the better.
I am also using a 9 volt dc 1 amp power supply to power the board of education and a 18 volt dc p[noparse][[/noparse]ower supply for the strobes and bell.
By the way i took out the diode temparary cuz it was not working rigt, it caused my bell to ring and then slowly die and turn off. I think i connected it wrong or it was not the right one. I cant see the diode causing it to reset since the buzzer works without it, howveer i willo figure the diode out and put it in to protect my basicm stamp.
Here is a picture of my bell and 2 of my board of education connected. Its the best shot if it i could get.
Hope it helps you to help me solve my problem.
Picture of Bell: http://image60.webshots.com/660/5/19/80/2160519800102854175yDowhC_fs.jpg
1st Picture of Basic Stamp: http://image50.webshots.com/650/4/40/51/2821440510102854175LoLOVi_fs.jpg
2nd Picture of Basic Stamp-Bell/Strobe Connections: http://image69.webshots.com/169/8/99/66/2419899660102854175fIYWrv_fs.jpg
Chris.
I don't see the relays or the transistors driving them. You do need to fix the transistor circuit as I suggested. The diode needs to be connected in parallel with the relay coil with the cathode (bar) connected to the +5V end and the anode connected to the transistor end (using my circuit).
For example, why is there a green wire lying next to (and seemingly contacting) the power plug to the Board of Education?
What relays are you using?
There are long wires coming off the Stamp pins for the relays and it's impossible to tell where the power wires (Vdd and Vss) associated with them run. These all can carry noise back into the Board of Education and potentially cause a reset. There are all kinds of ways to reduce this, anything from twisting pairs of wires together (usually a ground wire and another power or signal wire) to using shielded wire.
Anyways, any more suggestions?
Chris.
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- Stephen
Chris.
I thiunk i may have the answer thoigh, could it possiblty be because i had to twsit a bunch of wire to make the bell reach to the basic stamp, and some of that is CRAPPY dollar store speaker wire? Cuiz it seemed betetr when i used less wire and had the bell beside the stamp without the dollar store wire.
Chris.
Thanks.
Chris.
This section also shows you the correct way to wire a switching transistor for a relay.