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AST Transformer Used in Retail Security Tags
This AST transformer takes in 1.5V from a coin battery and produces 20V minimum output, to drive a Piezo alarm loud enough to deter theft.
Overview
ISL had supplied an AST transformer to Tyco/Sensormatic, a world leader in retail theft prevention. The transformer took in 1.5V from a coin battery and produced 20V minimum output to drive a piezo alarm loud enough to deter theft.
Challenge
ISL Products had to design an AST transformer that could be used in the existing design housing, which meant that the transformer could not exceed 12mm x 5mm. In addition to the size constraints, the customer needed us to do an unusual custom lead forming to properly fit the transformer into the customer’s current PCB configuration. The security tag that this transformer is powering had to be loud enough to alert security guards and robust enough to withstand multiple uses.
Solution
We created a transformer that met all of the customer’s parameters by utilizing unique properties of magnetics. We were able to save space in their unique PCB assembly and increase performance. The AST transformers were easily installed into each application and put into millions of units that are still working today.
Conclusion
ISL designed a compact AST transformer measuring no more than 12mm by 5mm that fit within the customer's existing security tag housing while boosting a 1.5V coin battery input to a 20V minimum output. Custom lead forming allowed the transformer to install directly into Tyco/Sensormatic's PCB configuration without any redesign of the surrounding assembly. By applying unique magnetic properties, ISL saved valuable board space while increasing performance and reliability, producing a piezo alarm loud enough to deter theft and durable enough for repeated use. This project shows how ISL can engineer compact, high performance transformers that have powered millions of retail security tags for years in the field.
