Help needed on multiple relays
Help needed on multiple relays
(OP)
I am building a project for my business and need some input on relays. Back 10 years ago I was able to do this but I have not been using relays and I am getting rusty. I need to set up a simple relay system with a push button switch to set the relay. When the relay is activated the relay will turn something on. The problem lies where I have 4 switches and if one is triggered I need the rest to become inactive and not work.
My end goal is to put this to ladder logic and control an Allen Bradley SLC 150 I bought off of ebay. I have the programming software from work. I tried to learn the language and make it happen but I am at a brain jam. So I thought if I go back to basics with the wiring diagram of a relay system then it might be easier.
Can any of you help?
Dave
My end goal is to put this to ladder logic and control an Allen Bradley SLC 150 I bought off of ebay. I have the programming software from work. I tried to learn the language and make it happen but I am at a brain jam. So I thought if I go back to basics with the wiring diagram of a relay system then it might be easier.
Can any of you help?
Dave





RE: Help needed on multiple relays
"Venditori de oleum-vipera non vigere excordis populi"
RE: Help needed on multiple relays
I am making a game so when I ask a question the players can ring out. When they hit the button a light turns on so I know who was first. After the first button is pushed the rest of the buttons can be hit as many times as they want and will do nothing.
Does that make better sense?
RE: Help needed on multiple relays
Yes. Just make sure each relay has at least 3 NC contacts and one NO contact. Wire each of the NC contacts in series with each opposing coil circuit. Wire the NO contact in parallel with the push button NO contact to the coil of that relay. When the button is pressed, it energizes the coil and seals itself in with the NO contact. The NC contacts will also open up and lock out the coil circuits for all of the other relays. so pushing the other buttons has no effect.
The only problem left is how to reset. You could easilly put one master button in series with all of them at the beginning of the circuit, or open up the neutral side of the circuit so all 4 coils drop out.
"Venditori de oleum-vipera non vigere excordis populi"
RE: Help needed on multiple relays
So what you are saying is each player position needs a total of 3 NC Relays and 1 NO relay and one pushbutton. The 3 NC relays will cut the power to the other 3 player position push buttons. The NO will cut the power to that persons push button.
so for 4 player positions i would need a total of 16 relays- 12 NC and 4 NO. Correct?
BTW thanks for your help
Dave
RE: Help needed on multiple relays
If you use the ones that have 11 pins, they have 3 sets of DPDT contacts, and if they have 14 pins there are 4 sets, which would make only 1 relay per player. 14 pin relays are sometimes difficult to find in stock however.
It may also be easier for you to look for what is called a "machine tool relay" available from an industrial electric supply house, because they can come configured with 1 NO and 3NC all on one relay.
"Venditori de oleum-vipera non vigere excordis populi"
RE: Help needed on multiple relays
I am not getting that far that way either.
thank you for all your help
RE: Help needed on multiple relays
http://www.zen22142.zen.co.uk/Circuits/Misc/quiz.h...
RE: Help needed on multiple relays
RE: Help needed on multiple relays
Last question on the 1k resistors will I still need them if the output is a relay? Or will the resistors have to be a different value.
This looks like a better way to go then the PLC I am trying to program.
Once again thank you all for your help.
Dave
RE: Help needed on multiple relays
The transistor's maximum collector current IC(max) must be greater than the load current IC. Load current IC = supply voltage Vs
Load resistance RL
The transistor's minimum current gain hFE(min) must be at least five times the load current IC divided by the maximum output current from the chip. hFE(min) > 5 × load current IC
Max. Chip current
Choose a transistor which meets these requirements and make a note of its properties: IC(max) and hFE(min).
There is a table showing technical data for some popular transistors on the transistors page.
Calculate an approximate value for the base resistor: RB = 0.2 × RL × hFE or RB = Vs × hFE 5 × IC and choose the nearest standard value.
Finally, remember that if the load is a motor or relay coil a protection diode is required
This is the relay that I found that I think will work.
http://www.jameco.com/webapp/wcs/stores/servlet/Pr...
Can someone translate the top and tell me what transistor and resistor I would need to activate this relay. Also
RE: Help needed on multiple relays
To safely handle the coil current the transistor's IC(max) should be about 100mA. Just connect the 1K resistor to the base of the transistor for each output.
As you can see from the diagram below, the transistor is an NPN.
The diode could be 50V, 1A (mainly because this is such a common spec - it's not critical, it just needs to be greater than 12V and able to handle the current generated when the coil is switched off)
RE: Help needed on multiple relays
Do any of you have a clearer schematic?
How excatly does one relay shut off another? Do you wire the initial pins together between relays?
I'm not understanding. sry.
RE: Help needed on multiple relays
it can be less than a buck !!
<nbucska@pcperipherals DOT com> subj: eng-tips
read FAQ240-1032
RE: Help needed on multiple relays
RE: Help needed on multiple relays
Maybe I'm reading this wrong, but it appears like you want this to eventually end up in the SLC150 you have.
If so, try this as a start.
---] [----]/[----]/[----]/[-------( )--
| 100 | 101 102 104 ?1
| |
|-] [-|
?1
---]/[----] [----]/[----]/[-------( )--
100 | 101 | 102 104 ?2
| |
|-] [-|
?2
Just repeat each rung as needed
Each switch will turn on only 1 output and turn off all other outputs, multiple switches will turn off all outputs and cycling power will turn off all outputs
100-104 will represent your switches as inputs and ? marks your relays as outputs (sorry, can't quite recall the output address in the SLC)
Ed