4120/4121, Line Powered Current Source Power Unit

The Dytran model 4120 is a 19-inch wide by 1 3/4-inch high, rack mountable, line powered current source power unit designed to power up to 6 channels of IEPE sensors and in-line charge amplifiers. The Dytran model 4121 is a 19-inch wide by 1 3/4-inch high, rack mountable, line powered current source power unit designed to power up to 12 channels of IEPE sensors and in-line charge amplifiers. The sensor signal, riding atop an approximate +10 volt bias level is decoupled from this DC bias by use of a 10µF coupling capacitor for each channel. The front panel of the unit contains 6 or 12 BNC output jacks for monitoring the sensor signals.

These power units contain a regulated DC power supply and constant current circuits which supply constant current DC power to sensor channels. The constant current sources can be individually adjusted to provide from 2 to 20 mA of drive current per channel. There is also a provision for operation from external +24 VDC batteries or DC power pacs for use where AC power is not available.

A rotary selector switch on the front panel allows the monitoring of the DC bias voltage of each sensor, and is a very useful troubleshooting tool for system checks. Readout is by a front panel mounted 10 segment LED DC voltmeter. Also connected to this rotary switch is a rear panel mounted BNC “monitor” jack which allows the user to look at the signal from the sensor connected to the selected channel. In this way, with a single oscilloscope, each channels signal may be inspected. A three position power switch on the front panel selects AC power or Ext DC power with an ‘off’ position included.

The standard version of model 4120 and 4121 operate from 115 VAC line power. A 230 VAC version, model E4120/E4121, is also available for use in countries where the normal voltage line if 230 VAC.