Table of Contents
Advertisement
5
Using Load Cards and Loads
Protection Devices
* The card was tested using a General Electric GE MOV II, MA series MOV.
† 10/1000mS refers to a standard pulse of 10mS rise and 1000mS to 50% decay of peak value.
‡ 8/20mS refers to a standard pulse of 8mS rise and 20mS to 50% decay of peak value.
5-16
MOV (Metal Oxide Varistor), or back-to-back zener diodes are
recommended for flyback voltage protection.
Figure
5-10. Zener Diode, MOV (Metal-Oxide Varistor) or
®
Transzorb
devices mounted at RTx or RTy (2 required per load
- 1 at NC and 1 at NO) provide current path for the inductive
load flyback. Select the protection device so that it conducts at a
voltage higher than the UUT's internal protection. If the device's
internal protection fails, then the added external protection
conducts to protect the UUT and the load card.
Figure 5-10 Typical Agilent E6175A Load Card Flyback Protection Circuit
+
16V
-
Typical small MOV (3mm) axial lead mounted specifications are:
Continuous DC voltage: 220 V
Transient energy (10/1000mS)
Transient peak current (8/20mS)
Varistor voltage @ 1.0mA DC: 300 Vdc Max
Maximum Clamping Voltage (8/20mS): 450 volts
Capacitance: 17 pF
Typical Transzorb
Breakdown voltage: 300 V max at 1mA
Reverse Standoff voltage: 250 volts
Maximum reverse leakage: 5 mA
Maximum peak pulse current: 5 A
Maximum Clamping voltage: 400 volts
Maximum temperature coefficient: 0.110%/°C
†
: 0.90 Joules (watt-seconds)
‡
: 100 Amperes
®
specifications are:
E6198B Switch/Load Unit User Manual
*
Refer to
Advertisement
Table of Contents
