You can set the duty cycle, the upper and lower limits of the duty cycle, and the working frequency to give you a good experience. Working Frequency: 1KHz~99KHz Adjustable, 1KHz Stepping, Default Frequency 20KHz, Accuracy About 1%.
eBay
5V 12V 10A Voltage Regulator PWM DC Motor Speed Controller Governor Stepless Speed Regulator LED Dimmer Power Controller
Aliexpress UK
High-performance DC motor speed regulator adopts thyristor BTA41-600B and 25A rectifier bridge. Reasonable circuit layout, easy to wire and use. Armature Output: About DC 10-210V. Maximum Power: 2000W motor.
eBay
5V 12V 10A Voltage Regulator PWM DC Motor Speed Controller Governor Stepless Speed Regulator LED Dimmer Power Controller module
Aliexpress UK
Max Current: 40A. 3:Only can work for Brush DC Motor ,Can't Work for Brushless Motor. Speed range: 0--100%.
eBay
5V 12V 10A Voltage Regulator PWM DC Motor Speed Controller Governor Stepless Speed Regulator LED Dimmer Power Controller
Aliexpress UK
Maximum current: 100A. Frequency: 15 kHz. We will try our best to reduce the risk of the custom duties. we will try our best to solve the problem asap.Your satisfactory is our goal. Color: Silver. Due to the difference between different monitors, the picture may not reflect the actual color of the item.
eBay
1.8V 3V 5V 6V 12V 2A PWM Dc Motor Speed Controller Variable Speed Regulator Governor Switch,Switch Function 1803BK
Aliexpress UK
Fit all kinds of dc lamp was dimming, all kinds of dc heater adjust the temperature. - Fit all kinds of general-purpose and have a DC motor speed with brush. Regulation range:5-100 percent. Frequency : 12k Hz.
eBay
1Pcs PWM DC Motor Speed Dimmer Controller 5V 12V 16V 10A Voltage Regulator LED Dimmer Dimming Module Stepless Speed Regulator
Aliexpress UK
DC 4.5-35V. United Kingdom.
eBay
5-20PCS 5V 12V 10A Voltage Regulator PWM DC Motor Speed Controller Governor Stepless Speed Regulator LED Dimmer Power Controller
Aliexpress UK
Duty Cycle adjustable: 5%-100%. Using high‑quality materials, strong and durable, has a long service life.
eBay
PWM DC Motor Speed Controller 6V 12V 24V 28V 3A Speed Regulator Switch
Aliexpress UK
Power: 12V 10A=120W;24V 10A=200W.36V 10A=360W. PWM Frequency: 21kHz. Current: 10A(rated), 15A(Max.)., adjustable from 1A to 10A. It is made with high quality circuit board which ensures a longer service life.
eBay
Digital PWM DC Motor Speed Controller 6V 12V24V48V Stepless Speed Controller Switch Controller
Aliexpress UK