Soft start, soft start device for motorized hand tools, motors and transformers. It can solve problems such as fuse blowing, irregular operation etc. due to instantaneous high current draw during the first operation. The system prevents the mains electricity from being connected directly to the device for a short time. Voltage passes through 2 series-connected 150-ohm 5w resistors. After about 1 second, the relay pulls, short-circuits the resistors and gives the voltage directly. No integrated, transistor etc., a simple and stable design.
Soft Starter Device Features
Approximately 1 second delay
Supports loads up to 2 kW
Simple design
Operating voltage 220 VAC without transformer
Part list
- R1,R2 150R/5W resistor
- R3 1M-OHM 1W resistor
- R4 220-OHM 1W resistor
- C1 470nF 275VAC
- C2 2200uF 25V
- D1 Zenner diode 1W 15V(16V)
- B1 DB105-HT bridge diode
- K1 FTR-K1CK012W Relay (12V 16A)
Soft Starter Circuit 24V Relay
Design of the same circuit that can be used with 24V relay… You can use 24V T type 20A or 24V 10A square relay. You do not need to make any changes on the PCB. One of the two models can be used. If you want to use a 12V relay, you should change the materials with different values according to the 12V version.
Note: PCB Drawings were prepared with Sprint Layout 6 Program. Checked, not tested.
ATTENTION The circuit works with high voltage, be careful, pay attention to the capacitor connections, if you connect the + – poles in reverse, there may be big explosions at high voltage, use a Fused Electric Line, protective glasses before operating the circuit.
source: arlisklep.pl/files/ARLI/AR116.pdf
