Furnace control apparatus and method

Electricity: motive power systems – Positional servo systems – With particular motor control system responsive to the...

Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

318 62, 318102, 318459, 318471, 318567, 388907, 388934, G05B 1302, F24H 300, G05D 2900

Patent

active

052724271

ABSTRACT:
An electric control for gas furnaces which controls a two speed main blower fan and an induction draft fan based on inputs from a room thermostat, a high limit and an ignition control including a gas valve. The control has a circuit board having a power supply for providing 24 volts DC current source to drive DC relays and a 5 volt DC power source to power a microprocessor. 24 volt AC input signals are coupled to the input ports of the microprocessor through current limiting resistors and to AC ground through pull down resistors. AC ground is also connected to the IRQ port of the microprocessor. The output ports of the microprocessor are connected to a relay driver which in turn is connected to the relays. Several breakaway tabs in the board provide optional features such as eliminating a normally provided draft delay timing function. Test pads are provided on the board so that the board can be tested during manufacture. An optional feature is shown comprising an LED which can be used to indicate the status of the system. Another optional feature incorporates a zener diode and resistor coupled to each input port to increase input thresholds. This feature is provided for use with power stealing electronic thermostats.
The control calibrates itself on a continuing periodic basis to read the AC inputs synchronously at the peak of their wave and switches the relays asynchronously based on the real time clock of the microprocessor.

REFERENCES:
patent: 4303383 (1981-12-01), Black et al.
patent: 4341345 (1982-07-01), Hammer et al.
patent: 4345162 (1982-08-01), Hammer et al.
patent: 4352349 (1982-10-01), Yoho
patent: 4648551 (1987-03-01), Thompson et al.
patent: 4659290 (1987-04-01), Kundert
patent: 4688547 (1987-08-01), Ballard et al.
patent: 4722669 (1988-02-01), Kundert
patent: 4789330 (1988-12-01), Ballard et al.
patent: 4860231 (1989-08-01), Ballard et al.
patent: 4863372 (1989-09-01), Berlincourt
patent: 4901918 (1990-02-01), Geary et al.
patent: 4934925 (1990-06-01), Berlincourt
patent: 4935606 (1990-06-01), Geary
patent: 4935607 (1990-06-01), Kadwell et al.
patent: 4978896 (1990-12-01), Shah
patent: 5076780 (1991-12-01), Erdman

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Furnace control apparatus and method does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Furnace control apparatus and method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Furnace control apparatus and method will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-311348

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.