NE555 DC motor speed control

[strawberry]

DC motor speed controller/LED dimmer NE555 based PWM learning kit
https://www.tindie.com/products/10008/
eBay auction: #302375968418


Input voltage range(auxiliary input only) : 15V...28V
Input voltage range max(screw terminal only): 0V...50V
MAX load current (Ta=25C° ) : 10Arms
Internal SMD fuse : 10A
Standby current max(auxiliary input only): 20mA
Load regulation(manual potentiometer) : 2...99%
Default PWM clock frequency (+/-5%) : 255Hz
Internal supply voltage(not accessible): 12V
Internal supply current(not accessible): 0.5Arms
PCB board dimensions : 54x54mm

Power screw terminal:
 + :Power supply positive terminal
M+:Output positive terminal
M-:Output negative terminal
 - :Power supply negative terminal

Accessible ports (header pitch 2.54mm):
 +: Auxiliary supply input
 +: Main supply output(with series resistor 10ohm)
 G : Ground
 O : NE555 low power PWM output
 G : Ground
 T : Timer ramp voltage(ramp capacitor 100nF to ground)
 C : Reference voltage control(reference filter capacitor 100nF)
 R : Reset(pull-up resistor 1k to 12V)
 G : Ground

[strawberry]

Finished PCB