EM-A23 is a braking-load controller designed to absorb regenerated electrical energy in DC motor systems. When a motor decelerates, it can operate as a generator and return energy to the DC supply, causing the supply voltage to rise.
When the voltage exceeds the adjustable switch-on threshold, the EM-A23 connects the braking load across the DC supply. The regenerated energy is then converted into heat, helping prevent excessive supply-voltage rise.
During rapid deceleration or when an overhauling load drives the motor, energy can flow from the motor controller back into the DC supply. If the power source cannot absorb this energy, the DC-bus voltage increases.
The EM-A23 monitors the supply voltage and activates the braking load when the selected threshold is exceeded. This creates an additional electrical load and dissipates the regenerated energy as heat.
The switch-on threshold can be adjusted from 18 to 39 V. It should be set above the highest normal supply voltage but below the overvoltage limit of the motor controller and other connected devices.
The switching hysteresis prevents rapid on/off cycling close to the selected threshold. The specified hysteresis is approximately 10%.
The unit is specified for a 5 Ω braking load. At a DC-bus voltage of 25 V, the corresponding current is approximately 5 A:
I = U / R = 25 V / 5 Ω = 5 A
The instantaneous braking power at the same voltage is approximately 125 W:
P = U² / R = 25² / 5 Ω = 125 W
An onboard LED indicates when the braking load is connected. During intermittent regenerative braking, the LED may switch on and off as the DC-bus voltage moves across the switching threshold and hysteresis range.
The EM-A23 includes overtemperature protection. If the monitored temperature reaches the specified limit, the protection prevents excessive heating of the unit.
The braking load can reach a high temperature during operation and must be installed with sufficient clearance from heat-sensitive or combustible materials.
| Function | Regenerative braking-load controller |
|---|---|
| Operating voltage | 12–40 VDC |
| Idle current | 10 mA |
| Adjustable switch-on threshold | 18–39 V |
| Switch-on current | 5 A at 25 V |
| Specified braking-load resistance | 5 Ω |
| Switching hysteresis | Typically 10% |
| Active indication | Onboard LED |
| Overtemperature limit | 190 °C |
Ordering larger quantities +100pcs.
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