Patent · US Expired

Thermal protection apparatus for a secure electronic appliance, in particular a postage meter

US5659454A · kind A · utility

167Cited by
2References
15Claims
0Family size

Assignee

Inventor

Key dates

Filing dateNov 30, 1994
Grant dateAug 19, 1997
Priority date
Expiry dateNov 30, 2014

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG07B2017/00338
  • WIPO fieldControl
  • WIPO sectorInstruments

Abstract

The apparatus detects the fact that a predetermined temperature threshold, in particular a low temperature threshold, has been crossed, and prevents any subsequent use of the appliance. The apparatus includes a reversible thermostatic switch capable of changing from a first stable state to a second stable state, and of delivering an alarm signal when it finds itself in the second state; and control means co-operating with the switch to respond to the alarm signal by delivering a disable signal for disabling the electronic appliance. According to the invention, the apparatus further includes a DC voltage source (15), an electrical or electronic component (17) capable of taking two states corresponding to said first and second stable states connected in a loop with the voltage source and the switch so that a current passing through the thermostatic switch causes a change from the first state to the second state.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.