Flow through electrical heat controller having asymptotic temperature control arrangement to avoid overshoot
US5390277A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 27, 1992 |
| Grant date | Feb 14, 1995 |
| Priority date | — |
| Expiry date | Mar 27, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05D23/24
- WIPO fieldThermal processes and apparatus
- WIPO sectorMechanical engineering
Abstract
This invention relates to the control of the temperature of heated fluid flow through a so-called single pass electrical heater. Specifically, a controller and accompanying flow circuit including a flow through single pass electrical heater is disclosed which provides for heating of water upon initiation of flow. A two stage control protocol is utilized for routing current under precise control to the heater element. In the first protocol utilized at start up to a control temperature limit slightly below the temperature set point, phase angle of current turn on with zero crossing current turn off control a 220 volt current to the single pass heater element. Once the control temperature is achieved, incremental adjustment of phase angle thereafter occurs with rapid asymptotical approach of the output temperature of the flowing water to a preselected temperature "set point" occurs. Problems relating to thermally inefficient storage of water as well as overshoot of the desired water output temperature are held to a minimum. Preferred use of the heating system in combination with a female hygiene douche is disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.