This device is a Solid State Relay (SSR) which uses semiconductors for silent, fast, and durable switching. Standard relays rely on mechanical contacts, which are slower, noisier and prone to wear and tear. This particular SSR also features electrical isolation in the form of an optocoupler, so you can rest assured that your control circuitry is safe from any high voltages being switched on the output of the relay.
You may be wondering why the image for this product shows a 25A SSR, but the product name and description refer to this as being a 12A SSR. Your eyes do not deceive you, there is a reason for this. After doing some research we discovered that many of the SSR’s which are imported from China/Taiwan (like these) tend to exaggerate when it comes to device ratings. We can confirm that these FQFER SSR’s fall into this category and have lower ratings than advertised on the product sticker / model number. This SSR in particular contains a BTA12 Triac which has a max current of only 12A. Another thing to note is clearance between the input and output traces of the optocoupler, which limits the maximum safe load voltage. The gap between the closest two traces is approximately 0.7mm, and based on the IPC-2221 standard for coated conductors, this is safe for use up 250VAC. In summary, as long as your load voltage and current does not exceed the maximum ratings described above these SSR’s are still perfectly usable.
Features / Specs
- Brand: FQFER
- Model: SSR-25 DA
- Control Voltage: 3 ~ 32VDC
- Load Voltage: 24 ~ 250VAC
- Max Load Current: 12A
- Optocoupler Part Number: MOC3063
- Triac Part Number: BTA12 1000B
- Dimensions: ~(60mm x 45mm x 22mm)
- Mounting Hole Size: M4