Apparatus and method for retaining cycle memory in electronic sterilizer controls
US5390322A · kind A · utility
Inventors
Key dates
| Filing date | Feb 1, 1991 |
| Grant date | Feb 14, 1995 |
| Priority date | — |
| Expiry date | Feb 1, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F11/1441
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Apparatus and methods for providing memory backup of sterilizer cycle progress in a sterilizer control apparatus are disclosed. The control apparatus includes a microprocessor operable to detect a drop or failure in power from the external source, a RAM for temporary storage of data from the microprocessor, and a clock chip. The clock chip and the RAM receive their power from a backup voltage source which is normally charged by the external power source. The clock chip includes a bit which can be set by receipt of an input signal. A comparator circuit is connected to compare the backup voltage VBAK to the minimum power required for accurately retaining memory in the RAM. When VBAK falls below the minimum required power, the comparator sends a signal to the clock chip to set the bit. After power is restored, the microprocessor checks the bit in the clock, and, if the bit is not set, continues operating the sterilizing cycle from the point at which it was interrupted by the power failure. If the bit is set, the cycle is restarted from the beginning.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.