How to wire this wireless remote switch for a camera? - Page 1
Forum section: electronics / beginners

author: MiniCheck
author_rank: Contributor
timestamp: September 02, 2025, 11:56:02 am
content: I have a camera that can be started/stopped remotely. Referring to the wiring diagram, you need to connect P7 to P11 of the 11-pin connector to start the camera and you disconnect it to stop it. You can basically put a switch there, from what I understand.With the wireless receiver, I would connect Input+ (receiver) to P11 (camera) and Input- (receiver) to P9 (camera) to power the receiver. Where would P7 and P11 connect with respect to the Normal Open (NO), Common (COM) and Normal Close (NC) pins on the receiver?Thanks!

author: Uunoctium
author_rank: Frequent Contributor
timestamp: September 03, 2025, 03:47:24 am
content: Since the white object in the image is an NEC relay with potential-free contacts, the connection between NO and Com should be correct. However, the camera's circuit diagram does not show enough detail.

author: Ian.M
author_rank: Super Contributor
timestamp: September 03, 2025, 08:01:57 am
content: I've got a nasty suspicion the camera +Batt voltage may be above 12V, exceeding the wireless receiver's max. supply voltage.

author: ledtester
author_rank: Super Contributor
timestamp: September 03, 2025, 08:40:02 am
content: Quote from: MiniCheck on September 02, 2025, 11:56:02 amTo be safe I would provide the receiver with its own power supply. Then the only connections between the camera and receiver would be the relay's NO/NC and COM connections.

author: MiniCheck
author_rank: Contributor
timestamp: September 03, 2025, 12:08:40 pm
content: Thanks for all the replies.I'll find out if +12V is the receiver's maximum voltage. I'll see if I can find more of the schematic - I found that online.You're right in that the battery, once charged, can be above +12V - I think it can be as high as +13V or more. Could I use a +5V regulator, for example? The camera will operate down to 9.5V. Below this it will switch off. This will also satisfy the receiver's requirements.Could you explain what the danger is with connecting the camera's power supply to the receiver which uses a relay to make/break a connection?Here's some more technical information on the receiver:1. Working voltage: DC3.7V-12V2. Quiescent Current: 6mA3. Working temperature: -40 Degree +80 Degree4. Receiver sensitivity: more than -110dBm5. Working frequency: 433mhz6. Relay Working Current: 30-35ma7. Working Mode: Momentary Toggle Latched adjustable8. Max load current: Max Load: 1A (have better Load less than 700ma)9. Size: 25*11*8MM10. Encoding Type: Learning Dot to add TransmitterThanks

author: BeBuLamar
author_rank: Super Contributor
timestamp: September 03, 2025, 12:49:59 pm
content: You don't know how the remote is wired. If the common or the NC of the relay output is connected to the negative terminal then you would short the camera power as by using the camera power to power the remote you must connect either the common or nc to the P11. If the internal one of these connected to P9 somehow you get a short.

author: Ian.M
author_rank: Super Contributor
timestamp: September 03, 2025, 01:22:42 pm
content: We know the remote receiver has aUD2-4.5NUrelay on it. It is therefore reasonable to assume that COM, NC and NO are isolated contacts. This can be confirmed by checking with a DMM on (high) ohms, measuring each contact in turn to both power pads (Input+, Input-) and reversing the test leads to test with both polarities. In all cases the reading should be over-range/open-circuit.

author: MiniCheck
author_rank: Contributor
timestamp: September 03, 2025, 02:02:30 pm
content: I appreciate the replies.I understand now why a separate power supply was recommended. Completely forgot that P7 is going to the same P11 that supplies the board!I don't have the receiver at the moment but I will check if the COM, NC and NO are isolated contacts when I receive it.Regarding using a +5V regulator to cut down the battery voltage, would that work or is there another way to do that?Thanks

author: MiniCheck
author_rank: Contributor
timestamp: September 08, 2025, 04:19:22 pm
content: Quote from: Ian.M on September 03, 2025, 01:22:42 pmJust received the devices and did the above checks. All tests were open-circuit. The only time it showed a reading was between that actual power inputs, Input+ and Input-.

author: Ian.M
author_rank: Super Contributor
timestamp: September 08, 2025, 06:44:36 pm
content: Yes. That confirms the receiver has volt-free contacts, so it can share a ground with the camera power supply, and even be powered from the camera battery if you can drop the voltage some. Ideally give it a regulated 5V supply. Try a low cost DC-DC buck module but if that puts out too much interference reducing its range and sensitivity, try a 7805 linear regulator (or better, something modern with much lower quiescent current and at least a 20V input voltage rating so its reasonably over-voltage resistant).