POWER
critical applications by David Bushnell, Inelco Hunter MD
T
ransient voltage suppressors (TVS) are crucial components for protecting electronic circuits from voltage spikes, also known as transients. These devices act quickly to divert excess voltage away from sensitive circuitry, preventing damage or malfunction.
This is extremely important in military and aeronautical applications where circuits are susceptible to events like lightning strikes, inductive load switching, or electrostatic discharge (ESD). Where lives are potentially at risk, dependable MIL-STD components are absolutely vital.
TVS devices are essentially over-voltage protection components that react quickly to voltage spikes. They are typically placed in parallel with the circuit they are protecting. When a transient voltage exceeds the TVS clamping voltage, the TVS becomes conductive, diverting the excess current away from the protected circuit. Once the transient subsides, the TVS returns to its high-impedance state, allowing normal circuit operation to resume. By clamping the voltage at a safe level, TVS diodes prevent damage to sensitive electronic components.
Essentials for safety-critical applications
Reliable operation: MIL-STDs establish uniform requirements for engineering, technical processes and methods, promoting consistency across different military services and contractors. Interoperability: MIL-STDs ensure that equipment and components can work together effectively, allowing for seamless communication and operation in diverse environments.
Quality Assurance: MIL-STDs provide a benchmark for the quality of military equipment, materials and processes, ensuring they meet stringent performance and reliability standards.
The Pros and Cons of TVS devices First of all, they are fast acting, extremely
22
important where lives are at risk. TVS diodes react very quickly to voltage spikes, providing rapid protection for sensitive electronic components. TVS components also provide a calibrated low clamping voltage which helps limit the voltage reaching sensitive components during a transient event. When a TVS diode fails, it typically fails in a short-circuited state, which is a safer failure mode than an open circuit. One disadvantage is that TVS components can be more expensive compared to other protection devices like Metal Oxide Varistors (MOVs) and Zener Diodes. But what price is too much for saving lives?
MIL-STD Grade Circuit Protection devices
As an example of state-of-the-art TVS circuit protection devices, the Protek PAL704-P15K36 and PAL704-P15K36T MIL-STD devices deliver circuit protection for 28 Volt applications like the DC Power Supply. They are 15 kilowatt silicon TVS devices, available from Protek distributor Inelco Hunter.
These TVS devices meet standards compliance for MIL-STD-704 and MIL-STD-19500, in addition to being RTCA DO- 160G standards compliant, and each device is 100 per cent tested.
Most importantly, both parts have a
operating and storage temperature is -55C
JULY/AUGUST 2025 | ELECTRONICS FOR ENGINEERS
to 150This is essential in demanding military and aeronautical applications.
Other applications requiring MIL- STD Circuit protection
TheTVS devices have a peak pulse power rating of 15,000 watts for a 1 MS wave-shape. This means that they can also be used in applications where induced lightning on rural or remote transmission lines present a hazard to electronic circuitry.
Design Support
In addition to offering the Protek MIL-STD TVS Circuit Protection devices as a standard product, Inelco Hunter offers technical support to help customers integrate the devices into their applications. In addition, Inelco Hunter’s engineering project requirements, including as-yet unformed product ideas, turning a concept into an outstanding product. A set of pre- design activities is worked through, critical documenting design challenges and identifying potential risks.
This added-value support is at the core of Inelco Hunter’s philosophy, and has been for over 30 years, setting them apart from the “stock and ship” distributors.
www.inelcohunter.co.uk/protection www.inelcohunter.co.uk
MIL-STD Grade Circuit Protection for safety-
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46
