EM-A1 is a compact auxiliary circuit board that enables symmetrical positive and negative analogue control on compatible Electromen motor controllers. It allows motor speed and direction to be controlled with a single bipolar command signal.
The nominal control range is −5 V to +5 V, with zero volts representing the neutral or stop position. Positive and negative control voltages select opposite motor directions, while the magnitude of the voltage determines the requested control level.
The EM-A1 converts a symmetrical analogue command into the unipolar speed and direction signals required by the compatible host controller. This enables forward and reverse operation from a single centre-referenced control signal.
The nominal full-scale input range is −5 V to +5 V. A dead zone of approximately ±20 mV around zero prevents small offset voltages or signal noise from unintentionally starting the motor.
The option card can provide a −5 V auxiliary supply for a centre-position potentiometer. Together with the positive reference available from the host controller, this allows the potentiometer to generate a symmetrical negative-to-positive control voltage.
When the EM-A1 is installed, the −5 V supply is typically made available through the direction-input terminal of the host controller. The exact terminal assignment must be confirmed from the documentation for the applicable controller.
Some compatible Electromen controllers provide input attenuation that may allow wider external control ranges, such as ±10 V or ±30 V. The host controller’s input-scale adjustment is then used to match the external command range to the EM-A1 control circuitry.
The permissible voltage range and adjustment procedure depend on the host controller. Compatibility and scaling must therefore be confirmed before applying more than ±5 V to the control system.
The EM-A1 must only be installed in compatible Electromen products equipped with the dedicated EM-A1 option-card socket. The host controller should be disconnected from its power source before the option card is installed or removed.
| Function | Unipolar-to-bipolar control conversion |
|---|---|
| Supply voltage | 5–6 VDC |
| Current consumption | Maximum 10 mA |
| Control-input impedance | 1 MΩ |
| Nominal input range | −5 V … 0 V … +5 V |
| Neutral dead zone | Approximately ±20 mV |
| Negative auxiliary output | −5 V |
| Maximum negative-output current | 5 mA |
| Installation | Dedicated EM-A1 option-card socket |
| Compatible products | Electromen controllers equipped with an EM-A1 option-card socket |
| Operating temperature | −40 … +70 °C |
Ordering larger quantities +100pcs.
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