Wiring radioshack SPST NEON ROCKER SWITCH - Page 1
Forum section: electronics / projects

author: Daniel_Reyes
author_rank: Regular Contributor
timestamp: October 24, 2015, 03:57:54 pm
content: Hello,Does anyone know how to wire this switch?http://www.radioshack.com/spst-lighted-rocker-switch/2750692.htmlI used my continuity checker to see what was the on position but I left the one bronze terminal unconnected. As a consequence, the switch does not light when it is on.

author: alsetalokin4017
author_rank: Super Contributor
timestamp: October 24, 2015, 04:51:48 pm
content: There are several possible pinouts. Usually they are like this:I installed a similar switch in an electric heater last winter and the first time I tried it I got it backwards and popped a circuit breaker when I switched it. So you may want to use a power strip with CB for initial testing, and don't button things up until you know it's right.

author: promacjoe
author_rank: Regular Contributor
timestamp: October 24, 2015, 05:07:44 pm
content: What voltage are you trying to use. it is probably a 120V AC lamp. I used to use these quite often. The lamp physically has no continuity between either pole or throw. That terminal goes to the common wire. using the continuity test function of your multimeter or a buzzer, determine the pole and throw of the switch. The remaining terminal should be The common terminal for the light.since basically you have already determined the above, just connect the remaining terminal to the common wire, and go from there.now all you have to do is determine which is the power in and the power out. With the switch in the off position, connect the hot to each of the remaining terminals. If the light comes on that is the output of the switch.

author: Daniel_Reyes
author_rank: Regular Contributor
timestamp: October 24, 2015, 05:16:48 pm
content: This is the datasheet I found for it.http://www.mouser.com/ds/2/209/Joytech_09042015_MS-101104-768049.pdfI still am not 100 percent certain on the layout and do not want to trip a breaker. I have 2 leads coming off the transformer I am using and 3 pins on the rocker. One of the pins on the rocker switch is bronze.

author: SL4P
author_rank: Super Contributor
timestamp: October 24, 2015, 10:49:05 pm
content: I know this sounds like an angry old rant, but the direction of this thread reminds me why they printNo user serviceable parts inside...

author: Daniel_Reyes
author_rank: Regular Contributor
timestamp: October 24, 2015, 10:57:06 pm
content: Quote from: SL4P on October 24, 2015, 10:49:05 pmWell thanks for that. Cherry on the top for my week.Sent from my SM-G900P using Tapatalk

author: Psi
author_rank: Super Contributor
timestamp: October 24, 2015, 11:01:51 pm
content: If you dont want to pop the breaker just put a load in series with the 110/220V when testing.That way any short will just power up the load.200W incandescent lamps works well for this.

author: Daniel_Reyes
author_rank: Regular Contributor
timestamp: October 24, 2015, 11:33:06 pm
content: Quote from: Psi on October 24, 2015, 11:01:51 pmIf i can find a ballast at home depot, i will try that.Sent from my SM-G900P using Tapatalk

author: Monkeh
author_rank: Super Contributor
timestamp: October 25, 2015, 12:01:10 am
content: The diagram makes it quite clear, as does any basic electrical sense.Connect the unused terminal to neutral. If you've got it wrong, the neon will always light. If you've got it right, the neon will light only when switched on. How to solve the former should be clear.

author: Deathwish
author_rank: Unknown
timestamp: October 25, 2015, 12:49:51 am
content: You will have to forgive my crappy drawing , but I used to make these piece rate as home work, all the ones I ever made work with a spring loaded pin inside the switch part pushing down on a copper plate that is on a fulcrum on the centre pin. this in turn pushes the plate in the opposite direction to that which you push the switch.

author: Daniel_Reyes
author_rank: Regular Contributor
timestamp: October 25, 2015, 01:00:51 am
content: Quote from: Deathwish on October 25, 2015, 12:49:51 amThank you for the drawing! I will study it further tomorrow since it is late here.Sent from my SM-G900P using Tapatalk

author: LukeW
author_rank: Frequent Contributor
timestamp: October 25, 2015, 02:44:54 am
content: As stated above you can use a simple continuity measurement to find the pins for the switch itself.The "extra" pin completes the circuit for the indicator lamp, so it's usually connected to ground (or AC neutral, in a line power application).If the lamp always stays on regardless of switch state, then you've connected the source to the pin that is connected to the lamp - which is the one that the load is supposed to be connected to, so you can just swap those two over.If one of the pins has a different color, eg. gold plated, then that indicates the lamp ground pin.Remember that the supply voltage has to be compatible with the type of lamp used - for example if the switch is designed for 240VAC use it will be perfectly safe to use it in a 12VDC application, but the neon bulb inside won't light up.

author: Daniel_Reyes
author_rank: Regular Contributor
timestamp: October 25, 2015, 02:56:45 am
content: Quote from: LukeW on October 25, 2015, 02:44:54 amThank you LukeW! I will try that tomorrowSent from my SM-G900P using Tapatalk

author: Ian.M
author_rank: Super Contributor
timestamp: October 25, 2015, 03:43:15 am
content: Quote from: LukeW on October 25, 2015, 02:44:54 amNot entirely true. Because the current goes to zero twice in each cycle in an AC circuit, any arcing when the switch opens is quickly extinguished. In a DC circuit, especially if there is an inductive load, the arc can be sustained for a considerable time or even indefinitely. It is therefore common for switches to have separate AC and DC ratings, with the DC rated voltage and usually current being significantly less than the AC rating.As a neon indicator wont work with low voltage DC, the switch may not be marked with a DC rating, but if you look up its datasheet, you will almost certainly find either a DC rating, or that the non-illuminated switch in the same series has separate AC and DC ratings.I would amend the above to "... it will be perfectly safe (if used within its DC rating) to use it in a 12VDC application ...". Ignoring DC ratings at best shortens switch life, and at worst leads to smoke or flames coming out of your front panel or even the switch explosively disassembling itself.

author: SeanB
author_rank: Super Contributor
timestamp: October 25, 2015, 06:41:02 am
content: Those switches typically will have a rating of 10(6)A 250VAC, 5A 28VDC. This means it will handle a 10A resistive load at up to 250VAC, and needs derating to 6A with an inductive or capacitive load like a motor or a transformer. The 5A DC rating also means you can only have up to a 28V DC supply voltage, so that the contact opening can clear the arcing safely.You can take the little neon lamp out using a gentle bit of persuasion on the side to bend out the rocker from the case to get it out ( note how the kit goes as you need to get it back together afterwards) and gently prise the cover from the white base. Then use a 3mm LED and a 2k2 0.25W resistor you replace the neon and the 100k resistor, putting the new ones in place and bending the leads to fit like the old ones did. Put the little spring back in, clip the cover together and gently clip back into the bottom section and you now have a 12V led version.For most of these switches the contact life is not the limiting factor, they tend to break long before the contacts wear out, unlike most other switches. Best use faston connectors to connect to the rear terminals instead of soldering, unless the application is such that it will only do 100 operations over the equipment lifetime. I have replaced a lot of these on stoves, mostly because either the top cracked ( user still uses it even though they can contact the live wiring) or the centre broke loose and all the bits flew out.

author: briselec
author_rank: Regular Contributor
timestamp: October 26, 2015, 10:12:59 pm
content: Quote from: Psi on October 24, 2015, 11:01:51 pmHaven't seen anyone use that technique in years. Used to be common once.

author: vk6zgo
author_rank: Super Contributor
timestamp: October 27, 2015, 02:37:04 am
content: I guess the OP has sorted this out by now,but,if he has found the two terminals which are connected with the switch in the "on" position,he knows that pair of terminals need to be in series with the Active or "hot" side of the Mains incoming,& one side of the transformer primary.The other side of the primary goes to the Neutral side of the Mains.With the DMM,it should be easy to determine the resistance of the transformer primary.(It may be quite low,but it won't look like a short circuit)Wire up the switch as suggested above,then with the switch "on" check the resistance between Active & Neutralof the device's power plug.If it looks the same as the primary direct,it is correctly wired--if it looks like a short circuit,rewire it,so it is correct.Ok,so far,so good,but here is where the fun comes in..........The third (unswitched) terminal should not have readable continuity to any other terminal at any time.(You can't see the Neon with your DMM,as it needs enough volts to ionise the gas inside it.)To make the Neon work,you need to connect that third terminal to Mains Neutral.The problem here is that if the terminal coming from the Mains Active & that going to one side of the transformer primary are swapped over,all will still be safe,but asMonkehpointed out,the Neon will always be on.If so,swap those two connections over,& everything will work as required.Using the resistance range of a DMM,everything can be wired up safely without having to connect the Mains.A Mains connection is only need for a brief test to see if the Neon works as required.After the resistance testing,return the DMM to "AC Volts" or "OFF"..

author: phaseform
author_rank: Regular Contributor
timestamp: August 26, 2017, 04:22:31 am
content: thought I'd just add thisSince I need to see the switch in the dark (light switch), I'll go for the bottom option withthisswitch.