I have a very simple project. I have a USB based 18650 Battery charger/ups unit and a solid state relay module.
What I am trying to do is the below:
The charger/ups unit is plugged into the wall using a usb charger
The usb charger is also powering the relay module (vcc and gnd)
The -ve output of of the UPS is connected to common of relay
NO of the relay is then connected to the -ve terminal of a 5v bulb
The +ve output of the UPS is connected directly to +ve terminal of the bulb
What I would like is if the power to the house goes out, the usb charger would lose power and therefore not power the relay, the relay would go to the NO config and the bulb would light up, using the output provided by the 18650 UPS.
This is not working. Relay module needs a signal at the IN terminal and I am not using a microcontroller or anything to do this.
Can I connect 5v directly to the IN terminal and would that put the relay module into an energized state?
From what I gather you are powering a relay that is powered on (NC contact open) when you have power. When you lose power the relay switches to its off state (NC contact closed). This then powers your UPS thingie. That should work but post an annotated schematic or a diagram showing how you have wired it.
It depends on the module you have, you can connect the input to 5V or to GND to activate the relay.
If you want the lamp to turn on when the relay loses power, you must connect it to the NC contact, not the NO.
If you wire the bulb to the NC contact of the relay, and activate the relay whenever the usb charger is powered, then the bulb will stay OFF while you have power. When power goes out, the relay will de-activate, making the connection on the normally closed contact and turning the bulb ON. As to whether the relay needs ground or +5V to activate doesn't matter, the loss of power from the usb charger will cause it to deactivate.
The idea is to have an emergency light setup, which lights up when the AC power from the outlet is no longer available (such as during a blackout or power outage).
I am not much of a circuit diagram guy, so I have done the best I could with powerpoint.
The 18650 Charger/UPS is a small device which has an input side which accepts 5v DC from the USB charger (a regular Phone charger) and charges the 18650 batteries. On the output side it gives out 5V dc using the energy stored in the 18650 batteries.
So when the AC power is on, the assumption is that the lights in the house are available and all is well. During this time the relay should not turn the 5v Lamp on. When a loss of power occurs, the AC outlet and hence the phone charger will stop outputting voltage and the relay should go into a state which allows the 5v from the UPS to flow to the 5v Lamp and therefore providing light.
In the picture I forgot to mention, the 5v output from the UPS unit is going to 'Common' pole of the relay.
Oh and I am using the Normally Closed pole instead of the Normally Open pole as shown in the diagram to connect the lamp. The NC terminal is the one that is not used, contrary to what is shown in the picture. My apologies.
So what I was wondering is, could I just place a jumper between vcc and signal terminals on the relay module and would that switch the relay module's state?
