Questions about the PWR-SWITCH

[RussellFrege]

I hope, I am in the right forum, I didin't find a better place to put this. I am also not super experienced with electronics.

I'm considering using the PWR-SWITCH with an ESP32 to control a photographic enlarger, and I have a few questions about the current version of the PWR-SWITCH.

1) The manual specifies 16A/3500W for resistive loads and warns about reduced relay life with inductive loads. Would a 110 VA transformer + 100 W halogen lamp be considered a suitable load for frequent switching with the PWR-SWITCH, also considering surge currents? And if not, do you have a suggestion that I could use instead (without high voltage splicing/soldering).

2) Is there any anticipated switching on/off delay, and if yes, how long approximately?

3) Is it OK to just use a GPIO to switch it, or is it safer to use the 5V supply through a MOSFET controlled by the ESP32, since the minimum is specified at 3V and HIGH should be 3.3V is only guaranteed to be 2.64V as far I understand.

Thanks in advance.

[LubOlimex]

1. You have to check the transformer inrush current and what the halogen can draw. For occasional or moderate operation I would expect this load to be reasonable, but we cannot guarantee relay life for frequent photographic-timer switching without measuring the actual inrush and testing the combination.

2. The relay manufacturer specifies:

- Switch-on/operate time: maximum 20 ms
- Switch-off/release time: maximum 10 ms

3. You are correct, typically you can directly control the PWR-SWITCH via 3.3V GPIO but the minimum guaranteed for ESP32 chip is 2.64V so this might be a problem in the worst case scenario. MOSFET will be required.