How to Connect the Light on a Switch - Page 1
Forum section: electronics / beginners

author: Larsson55
author_rank: Regular Contributor
timestamp: June 02, 2022, 01:07:40 am
content: The attached picture shows 2 12VDC ON/OFF switches and each one has 3 terminals, none are marked with any numbers but one is brass color and the other 2 are silver color. One of these silver color terminal must be for the light on the switch.I will assume the brass color terminal is where the positive wire (RED) will go but I don’t know the rest. Can you please tell me how to finish the connections?Thanks

author: SmallCog
author_rank: Frequent Contributor
timestamp: June 02, 2022, 02:02:06 am
content: With the switch in the I position check resistance from that brass coloured terminal to the other 2 terminalsWhichever terminal has the lowest resistance will be your typical switched terminal. Double check this with the switch in the other position.I expect that the second terminal will need to be provided an earth to get the light to light up, similar to:https://www.sparkfun.com/products/11155

author: CaptDon
author_rank: Super Contributor
timestamp: June 02, 2022, 02:12:36 pm
content: This reminds me of a recent thread of a lighted switch that went over three pages long.

author: BeBuLamar
author_rank: Super Contributor
timestamp: June 02, 2022, 02:51:37 pm
content: The I is on. O if off. They stand for 1 and 0.The center tab is for power in and the switch would connect the center tap to the other silver tap when it's turned on. The brass color tap is for the return for the indicator light in the switch.For example if you connect +12V to the center tab. When you turn the switch on the +12V connected to the built in lamp as well as the other silver tab. Connect the negative to the brass tab so the indicator lamp can work.

author: Larsson55
author_rank: Regular Contributor
timestamp: June 02, 2022, 08:02:06 pm
content: My thanks to all for the excellent help. Now I understand and it will be easy to finish my connections

author: inse
author_rank: Super Contributor
timestamp: June 02, 2022, 08:11:01 pm
content: Quote from: CaptDon on June 02, 2022, 02:12:36 pmYeah, that was hilarious

author: Larsson55
author_rank: Regular Contributor
timestamp: June 02, 2022, 10:12:12 pm
content: Sorry guys, theory is good but in practice I stumbled!Is the attached schematic correct or I got it all wrong?Thanks

author: james_s
author_rank: Super Contributor
timestamp: June 02, 2022, 10:23:14 pm
content: No, that's wrong. You need to connect power and ground to the correct terminals on the switch, then the load is connected between the remaining terminal on the switch and ground.

author: Larsson55
author_rank: Regular Contributor
timestamp: June 02, 2022, 10:35:29 pm
content: Thanks James, I’m not very good in electronics. What you are saying I think I have done that so if we use my picture and the brass terminal is 1, then the middle is 2 and the last is 3 where my switch and light will connect?Thank you

author: Larsson55
author_rank: Regular Contributor
timestamp: June 02, 2022, 10:49:28 pm
content: Perhaps like the attached?

author: james_s
author_rank: Super Contributor
timestamp: June 03, 2022, 12:29:50 am
content: No, that still isn't right. One of the terminals on the switch needs to go straight to + supply which you have, another needs to go straight to ground, the remaining one needs to go straight to the load, the remaining wire on the load goes straight to ground.

author: Larsson55
author_rank: Regular Contributor
timestamp: June 03, 2022, 01:08:18 am
content: Apologies for my ignorance James, I would have never been able to figure this out without your wonderful schematic which although I have no problem to connect as shown I still have to study to understand how it works. In electrical work I have learned to avoid “smoke” you must understand what you are doing.Much appreciated

author: BeBuLamar
author_rank: Super Contributor
timestamp: June 03, 2022, 01:43:42 am
content: Quote from: james_s on June 03, 2022, 12:29:50 amIt's not quite right! The center pin should be connected to the positive of the voltage source and the outer silver pin to the load. Do it your way it would still work but the indicator light in the switch would be on all the time.

author: Larsson55
author_rank: Regular Contributor
timestamp: June 03, 2022, 02:13:33 am
content: Quote from: BeBuLamar on June 03, 2022, 01:43:42 amNow I'm confused and I dont qualify to comment. Can someone conclude the correct option?

author: IanB
author_rank: Super Contributor
timestamp: June 03, 2022, 02:22:04 am
content: Quote from: Larsson55 on June 03, 2022, 02:13:33 amHow about if we Google it?https://letmegooglethat.com/?q=wiring+diagram+for+illuminated+rocker+switch

author: Larsson55
author_rank: Regular Contributor
timestamp: June 03, 2022, 03:13:49 am
content: Sorry, I made a posting mistake here

author: Larsson55
author_rank: Regular Contributor
timestamp: June 03, 2022, 03:18:01 am
content: What James_s posted along with the schematic is the correct way to do it. I just did it and the switch turns ON/OFF the load along with the light on the switch. The post later which states to do it otherwise the light on the switch stays ON all the times and the load switches ON/OFF.Many thanks to all

author: Larsson55
author_rank: Regular Contributor
timestamp: June 03, 2022, 11:09:22 am
content: Now I got the 12VDC switch wiring working I have another question. I’m using a DIN rail for my connections and for the 12VDC I have 2 DIN terminals one for the POS and one for the NEG. Can I branch from the same terminals to feed 2 different items?It means from the same 12VDC DIN terminals of POS & NEG one pair of wires will feed a ON/OFF switch for a fan and another pair will feed another ON/OFF switch for a light. I see no problem but I better ask.Thank you