June 2010

Doc ID 8159 Rev 3

1/8

AN1296

Application note

Ring wave tests with ACS108 driving valves and pumps

Introduction

In this application note, test results obtained using ACS108 AC switch devices are

presented in order to analyze their behavior when subjected to standard ring wave surges.

The behavior of these devices subjected to a 1.2/50 µs impulse wave is specified in the

datasheets.

The test procedure is described in the UL858A standard. The only difference with the tests

below is that the normalized waveform is applied directly to the semiconductor and the load

(refer to Figure 1).

No coupling network is used to apply the surges while the system is connected to the mains

terminals. The only stress is due to the breakover turn-on current. The current conduction

during half mains cycle is not an issue.

The ACSs are not triggered by their gate - they turn on by over voltage when the generator

voltage exceeds their clamping level. The surge is then applied across the load and the load

current flows through the ACS™ which is in the on state.

Figure 1.

Test diagram

All the following oscillograms have been produced using the equipment listed below:

●

Tektronix TDS754A scope

●

Tektronix voltage P6013A probe (1/1000 ratio)

●

Eurocraft pulse current transformer (1 V /10 A ratio)Tektronix TCP202 current probe

TM: ACS is a trademark of STMicroelectronics

OUT

G

COM

Integrated

driver

Over voltage

protection

( Trisil™-like)

AC power

switch

Ringwave

generator

RG = 150

W

IOUT

Load

TM: Trisil is a trademark of STMicroelectronics

www.st.com