Today, when we think about controlling the output of a power supply, we usually think about digital control via a USB port or some other network interface. That's not the only way to control a power supply, though. Analog control is still used in many industrial applications, and it’s also a good choice if you have fairly simple control needs.
The optional Analog Programming (APG) Interface allows you to control the Sorensen XT Series and HPD Series of DC power supplies with either 0-10 VDC signal or a 0-10 kΩ resistance. You connect these signals to the power supply via a female DB-25 connector on the unit's rear panel.
The APG's interface provides the following features:
- Programmable output voltage and programmable current limit using either a 0-10 VDC programming signal or a 0-10 kΩ resistance. In this mode, both the offset and range are externally adjustable.
- Fixed programming of output voltage and/or current limit using an available 10V reference (10mA max source).
- 0-10 V readback of output voltage and current with externally adjustable offset and range.
- Status signals for programming mode, operating mode, OVP (over voltage protection) flag, and output fail flag.
- Adjustable over-voltage protection (OVP) with reset and flag.
- TTL shutdown with selectable positive or negative logic.
- Tracking for multiple supplies of the same output.
The performance specifications are shown in Table 1 below:
|0-10 VDC for 0-100% of rated
voltage or current ±0.1%,
0-10 kΩ for 0-100% of rated
voltage or current ±0.1%
|OVP Trip Range||3V to full output + 10%|
|Remote ON/OFF||2 to 25Vdc high. <0.8Vdc low.
As an example of how to use the features of the APG interface, let's look at how to program the supply's output voltage with a 0-10 VDC voltage source:
- Select remote voltage programming by moving the rear panel switch S1-5 (remote voltage program select) to the ON (closed) position. Or, connect J5 pin 7 (remote voltage program select) to J5 pin 6 (auxiliary ground). As these two control functions are wired in parallel, they function as a logic OR.
- Connect the voltage source between pin 17 (voltage program) and either pin 4 or pin 5 (program return).
- Vary the external voltage from 0-10 VDC to cause the power supply output to vary from 0-100% of rated output voltage. You may set the power supply's output current limit using another source or the front panel current limit control.
The procedure for programming the output voltage with a 0-10 kΩ resistance and programming the output current with either a 0-10 VDC signal or a 0-10 kΩ resistance is very similar to this.
For more information on how to use remote analog programming, or isolating control signals, contact AMETEK Programmable Power via e-mail firstname.lastname@example.org or call 800-733-5427.