The document describes the DMS-EB-RMS board, which allows the true rms value of ac signals to be displayed on 5V-powered DMS-30PC/LCD digital voltmeters. The board has an input range of 0-750Vac for ±2V meters (1Vac resolution) or 0-199.9Vac for ±200mV meters (0.1Vac resolution). The board also accommodates user-installed modifications such as input-scaling resistors and isolated +5V dc/dc converters.
The DATEL DMS-EB-RMS is an AC-to-RMS converter application board for 5V-powered DMS-30PC/LCD digital voltmeters. It allows those meters to display the true rms value of ac inputs, with a stated input range of 0-199.9Vac for ±200mV meters or 0-750Vac for ±2V meters.
The one-page document lists functional specifications, ordering information for the board and two bezel assemblies, and technical notes. It also includes power and safety precautions and a schematic diagram; the AC HI and AC LOW inputs are not electrically isolated from the 5V supply, and a dedicated transformer-isolated +5V supply with a minimum 1kV breakdown rating is required when measuring signals derived from ac power mains.
| Vac Measurement Range (±200 mV meters) | 0 to 199.9 Vac |
|---|---|
| Vac Measurement Range (±2 V meters) | 0 to 750 Vac |
| Conversion Accuracy | 0-200 Vac ±0.5%; 0-750 Vac ±2% |
| Crest Factor | 3, maximum |
| Input Frequency Range | 40Hz to 2kHz |
| Primary Operating Power | +5V (±5%) |
| Current Consumption (Board Only) | +0.5mA typ., +1mA max. |
| Operating Temperature Range | 0 to +60°C |
| Storage Temperature Range | –20 to +75°C |
| Humidity | 0 to 95%, non-condensing |
| Dimensions | 2.02" (51.31mm)W x 0.83" (21.08mm)H |
It works with 5V-powered DMS-30PC/LCD digital voltmeters and also with DMS-40PC/LCD meters, according to the document.
The stated input frequency range is 40Hz to 2kHz.
Its primary operating power is +5V (±5%).
No. The AC HI and AC LOW inputs are not electrically isolated from the 5V supply; AC LOW is connected directly to 5V RETURN.