Model 507 and Model 508 Current Pulsers

1Overview

The Model 507 and Model 508 are high current pulse generators from the Directed Energy Division of Berkeley Nucleonics. Both act as firesets for high-energy initiator testing, delivering controlled current pulses into low-impedance loads such as airbag squibs, detonators, and pyrotechnic igniters. They cover different ranges of current, pulse width, repetition rate, and compliance voltage, so this page presents each model against its own datasheet.

The Model 507 is the high-current unit. It produces adjustable current signals up to 25 A per channel from a 44 V minimum bank voltage, with pulse widths from 100 µs to 100 ms and delays to just under 100 seconds, in 200 ns steps. It ships in a benchtop chassis with 2 or 4 independent channels and a TTL Sync output referenced to T0.

The Model 508 is the precision, fast-edge unit. It delivers 0.10 to 6 A per channel into a 19 to 22 V compliance with sharp edges (about 550 ns resistive rise time at 6 A) and adds integrated 4-wire resistance measurement, current and voltage monitors, and statistical firing modes. It ships in a 19-inch 2U rackmount chassis with 2 or 4 channels.

Both pulsers ship from the same San Rafael, California build with one support path.

2How They Work

Both models are current sources rather than voltage sources. Each regulates current into the load and takes its pulse timing from an internal rate generator or an external trigger, with every channel holding its own independent delay and pulse width.

The Model 507 favors wide, high-slew current pulses into a higher 44 V compliance, which suits slowly repeated, large-charge firing. Timing comes from a 5 MHz, 25 PPM crystal oscillator, with delay and pulse width set in 200 ns steps and 100 ns RMS jitter. Each output drives 0 to 25 A into loads from roughly 1 to 10 ohm, with a slew rate above 2.5 A/µs.

The Model 508 favors faster, lower-voltage pulses across a broad span of repetition rates. Its internal rate generator spans 0.01 Hz to 40 kHz with 10 ns RMS jitter and supports single-pulse and burst output of 2 to 250 pulses. Isolated current and voltage monitor outputs let the operator capture the delivered pulse on an oscilloscope, and integrated 4-wire resistance measurement characterizes the bridge wire before and after firing.

3Model 507 vs 508

The two models trade current for speed and measurement. The table below is the at-a-glance comparison; the verbatim datasheet specifications for each model follow in their own sections.

*Model 507: contact us for other options for amperage and pulse widths. Model 508: maximum pulse width is limited by current amplitude (1 A can go up to 100 s, 6 A is limited to 300 ms).

4Model 507 Specifications

The Model 507 ships in a 2-channel (507-2C) or 4-channel (507-4C) configuration, each output digitally controlled and independent. The following values are taken from the Model 507 datasheet.

*Contact us for other options for amperage and pulse widths.

5Model 508 Specifications

The Model 508 ships as the 508-2C or 508-4C in a 19-inch 2U chassis with current sensing and resistance measurement. The following values are taken from the Model 508 datasheet.

*Maximum pulse width is limited by current amplitude. 1 A can go up to 100 s and 6 A is limited to 300 ms.

6Triggering & Safety

Both models take pulse timing from an internal rate generator or an external trigger. The Model 507 uses a 3 VDC trigger threshold (3 mA into an optoisolator) on a 1000 ohm input, keeping the trigger path isolated from the high current output stage, with a 10 µs external-trigger-to-T0 delay and a built-in safety interlock. A TTL Sync output referenced to T0 serves as a reference for cameras and instrumentation, and 12 memory slots hold complete setups.

The Model 508 triggers from selectable front or rear inputs at a 2 to 15 V level on a 1 kohm input, with rising or falling slope, a 100 mV level threshold, a trigger filter that rejects glitch and runt pulses, 300 ns insertion delay, and 10 ns jitter. Safety is layered: a removable keyed front-panel fire enable, mechanical and software interlocks, a remote shorting interlock, and internal error checking that verifies the control circuit. The 508 fires single pulses or bursts of 2 to 250 pulses and provides front and rear sync outputs (T0, channels A through D).

7Applications

The Model 507 and Model 508 suit firing and characterization of low-impedance, high-energy initiators where a specific current, pulse-width, and repetition-rate range is needed:

• Airbag deployment testing, squib detonation
• Detonator and pyrotechnic initiator testing
• Igniter triggering
• Explosive testing and ballistics work
• Model 507. High current firing to 25 A into a 44 V compliance for large-charge initiators
• Model 508. Precision 0.10 to 6 A firing with 4-wire bridge-wire resistance measurement, plus statistical sensitivity testing (Bruceton, Neyer)

8Ordering Information

Contact

For a quote, configuration help, or application support, reach the Berkeley Nucleonics team.

Email: info@berkeleynucleonics.com
Phone: 800-234-7858