Motech LPS-300 series
The Motech LPS-300 series of programmable power supplies consists of 5 1-channel or 3-channel devices with optional RS232 connectivity.
The devices were also sold as the Amrel LPS-301 by American Reliance and partly under further brands.
Specifications
The models differ only in the number of available channels, maximum voltage and maximum current output:
| Model | Power Output | Channels | Voltage/Current |
|---|---|---|---|
| LPS-301 | 30 W | 1 | 30 V/1 A or 15 V/2 A |
| LPS-302 | 60 W | 1 | 30 V/2 A or 15 V/4 A |
| LPS-303 | 90 W | 1 | 30 V/3 A |
| LPS-304 | 70 W | 3 | ±30 V/1 A or ±15 V/2 A; 5 V/2 A |
| LPS-305 | 165 W | 3 | ±30 V/2.5 A; 3.3 or 5 V/3 A |
These specifications are common to all models:
| 30 V Channels | ||
|---|---|---|
| Voltage | Current | |
| Programming Resolution | 10 mV | 1 mA |
| Programming Accuracy | 0.05% + 20 mV | 0.15% + 5 mA |
| Readback Accuracy | 0.1% + 20 mV | 0.2% + 5 mA |
| Ripple (10 Hz to 20 MHz) | 1 mV rms / 10 mV p-p | 10 mA rms |
| Load Regulation | 0.001% + 1mV | 0.01% + 1mA |
These specifications apply only to models having a 3.3V/5V output:
| 3.3/5V Channel | ||
|---|---|---|
| Voltage | Current | |
| Ripple (10Hz to 20MHz) | 2 mVrms / 10mVp-p | 10mArms |
| Load Regulation | 0.001% + 1mV | 0.01% + 1mA |
Protocol
The communication with the device is via an optional RS-232 port (Option 02). The port parameters are 2400 Baud, 8n1.
All commands are plain ASCII. All commends are terminated by \r, \n or \r\n. Another command sent before reception of the reply (usually OK) will be ignored. It seems that numerical parameters can be entered with an arbitrary number of digits.
| Commend | Reply | Description |
|---|---|---|
| BEEP(0|1|2|3) | OK | Beeper function 0: disable; 1: enable; 2: force alarm 3: off |
| CALI(0|1|2) | ? | Calibration 0=end; 1=begin; 2=input parameter There seem to be no plausibility checks and the description is incomplete. Messing around with the calibration is strictly discouraged and can cause odd behaviour! |
| HELP | Output command list (several lines) | |
| IOUT(n) | d.dddd | Current readback |
| ISET(n) d.dd | ? | Set output current |
| LOWA(0|1) | ? | CC output compensated 0=off; 1=on (what is that?) |
| MODEL | LPS- | Get model number (seems to work incompletely!) |
| OUT(0|1) | OK | Disable/enable output |
| STATUS | <decimal> | Working status, bitwise encoding. Bit 0, channel 1 mode: 0: CV 1: CC. Bit 1, channel 2 mode: 0: CV 1: CC. Bit 3,2, tracking: 00: independant; 10: to channel 1; 11: to channel 2. Bit 4, digital output 3: 0: off; 1: on. Bit 5, digital output voltage: 0: 5 V; 1: 3.3 V. Bit 6, output 1/2: off; 1: on. Bit 7, output 3: 0: ok; 1: overloaded. Bit 8, Fan: 0: off; 1: on Bit 9, beeper: 0: off; 1: enabled Bit 10, CC output compensated: 0: off; 1: on |
| TRACK(0|1|2) | ? | Tracking 0=independant; 1=from channel 1; 2=from channel 2 |
| VDD(0|3|5) | ? | Set ("digital") output 3 0=off; 1=3.3 V; 5=5 V |
| VERSION | Ver-1.17 | Get version number. |
| VOUT(1|2) | dd.ddd | Voltage readback |
| VSET(1|2) dd.ddd | ? | Set output voltage |
| * | \r\nERROR | Error |