Transient Specification ISO7637-2:2004

ISO7637-2:2004 forms the basis of nearly all the specific manufacturer specifications and the new NSG5000 system enables all the core pulse parameters to be tweaked to meet an individual manufacturer specification.  

This system will enable TRaC customers to benefit from an increased scope of manufacturers test specifications with most of the main vehicle manufacturer specifications covered, Ford, BMW, GM, Toyota to name a few.

To complement our growing military testing scope this purchase also enables us to offer testing to DEF STAN 61-5 part 6 for equipment fitted to military vehicles.

A brief explanation of the pulses contained within ISO 7637-2:2004 is given below

Pulse 1

This pulse simulates transients due to supply disconnection from inductive loads. The pulse is typically 1 or 2ms in duration with test voltages up to 600V.

Pulse 2a

This pulse simulates transients due to sudden interruption of currents in a device connected in parallel with the Equipment Under Test (EUT) due to the inductance of the wiring harness. The pulse is 50µs with test voltages up to 50V.

Pulse 2b

This pulse simulates transients from d.c. motors acting as generators after the ignition is switched off. The actual pulse itself is a 1ms dip to 0V followed by an exponential waveform that lasts for up to 2 seconds with initial voltages of up to 10V or 20V depending upon the system voltage.

Pulse 3a and 3b

These pulses are a simulation of transients which occur as a result of the switching processes and are very fast high voltage transients with voltages up to 200V (positive and negative) and durations of 100ns.

Pulse 4

This pulse simulates supply voltage reduction caused by energizing the starter-motor circuits of internal combustion engines. The pulse itself is a series of ramped dips and lasts for anything up to 20 seconds.

Pulse 5a and 5b

This test is a simulation of load dump transient, occurring in the event of a discharged battery being disconnected while the alternator is generating charging current and with other loads remaining on the alternator circuit at this moment. These pulses can be quite damaging as the can contain a significant amount of energy. With voltages up to 174V and durations up to 400ms.