Manufacturer: Tohkemy Corporation
Model: CMK
Features
The CMK Series adds an electric control motor to the manual flow-adjustment mechanism of CM-type spring-back diaphragm pumps, enabling automatic stroke length control. It integrates seamlessly into proportional control systems for:
Feedforward Control: Turbidity, raw water flow rate.
Feedback Control: Residual chlorine, pH level.
Dual Control System Capability
Combining stroke adjustment with motor speed control (via VS motor or inverter) enables dual-parameter control (e.g., flow rate + concentration) across an ultra-wide dosing range.
Compatible Pump Models
CM-Y Series: CM-2Y to CM-120Y
CM-R Series: CM-4R to CM-6R
CM-L Series: CM-1L to CM-3L
Specifications
| Nominal model of control motor | K-4 |
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| Model of control motor | MCH-1C |
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| Manual setting devices | Equipped |
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| Type of servo motor | Reversible condenser motor with brake |
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| Voltage / Frequency | AC 100V 50/60Hz |
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| Output | 8W |
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| Rated revolution | 60 Hz:1,450 rpm / 50 Hz:1,200 rpm |
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| Feed-back resistance | 200Ω 1.5W |
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| Operating time | 49/58 SEC(60/50Hz) |
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| Operating angle | 0-300° |
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| Ambient temperature | -20 – +60℃ |
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| Protections | Outdoor drip-proof |
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| Color | Munsell 2.5PB 2.5/7 |
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| Weight | 5kg |
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Control motor circuit

| No. of terminal | Explanation |
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| 1 | AC100V | Common |
| 2 | AC100V | 100% side |
| 3 | AC100V | 0% side |
| 4 | Feed-back signal | 0% side |
| 5 | Feed-back signal | Common |
| 6 | Feed-back signal | 100% side |
Control motor
Line between (1) and (2) energized: Turning to maximum stroke
Line between (1) and (3) energized: Turning to minimum strokeProportional controller and positioner block diagram
