We were recently commissioned to design and build an automatic warning alarm for use with a screen printing flash dryer by a custom t-shirt print company in USA.

A flash dryer is a special heater which rapidly cures the ink printed onto the t-shirt or sweatshirt. If a shirt is left for too long in the flash dryer it will be scorched and ruined, and with a bit more time even the wooden shirt board around which it is fitted can be ruined. Therefore it is desirable to have a warning alarm sound if a shirt is left in the flash dryer too long by the operator.

The controller we made is pictured above. There is a microswitch on the flash dryer which closes when the flash dryer is closed over a shirt. The user can programme our controller with the maximum number of seconds they want to leave a shirt in the dryer – e.g. 15 or 20 seconds – and then if that time is exceeded the on board relay closes for 3 seconds to sound a loud alarm connected to it.

When the operator opens the flash dryer, the microswitch opens and the controller automatically resets ready for the next time the flash dryer is used.

If you need any kind of automatic sensor or timer based alarm system, email neil@reuk.co.uk with details of your requirements.