The HK1657 time relay is a ready-to-use enclosed device designed to control electrical loads using an external +12 V control signal. The timer starts counting after the control signal is removed.
When power is applied, the relay remains OFF and waits for a +12 V signal on the control input. When +12 V is present, the relay switches ON and stays active until the control signal is removed. After the +12 V signal drops, the preset time starts counting. Once the time expires, the relay switches OFF and returns to standby mode.
The device features two operating modes selectable via jumper W2. In one mode, the timer runs independently of further control signals. In the other mode, any new +12 V signal during an active cycle resets the timer and the relay remains ON until the signal is removed.
The delay time is adjustable from 1 to 60 seconds or minutes using a trimmer potentiometer. The time unit is selected via a jumper with power OFF. LED indicators display power and relay status.

Technical Specifications:
Operating principle: +12 V controlled time relay, delay after signal removal.
Delay time: 1 - 60 seconds or minutes.
Operating modes (jumper W2):
- W2 closed - timer runs regardless of subsequent +12 V signals,
- W2 open - each +12 V signal resets the timer.
Time unit selection (jumper W1):
- W1 closed - seconds,
- W1 open - minutes.
Time adjustment: trimmer potentiometer.
Indication:
- power LED,
- relay ON LED.
Dimensions:
- PCB: 49 x 29 mm,
- Enclosure: 55 x 35 x 20 mm.
Relay output:
- Normally Open contact (NO),
- Common contact (COM),
- Normally Closed contact (NC).
Relay ratings:
- 15 A / 125 V DC,
- 15 A / 24 V DC or AC,
- 10 A / 250 V AC.
Supply voltage: 10 - 14 V DC.
Current consumption:
- relay OFF: 8 mA,
- relay ON: 48 mA.

This product is a boxed finished product.
It is also available as a fully assembled module (without box) - Product code 1607 (separate product).