公开(公告)号：US20040174265A1

公开(公告)日：2004-09-09

申请号：US10384303

申请日：2003-03-07

Applicant: Ranco Incorporated of Delaware

Inventor： John Kociecki ,  Yelena N. Kaplan

IPC: G08B017/12

CPC classification number: F23N5/123 ,  F23N2023/00 ,  F23N2023/08

Abstract: An analog flame sense circuit is provided that utilizes the flame rectification method of sensing flame. The circuit uses an AC voltage source and discrete components to provide the sensing of the flame current. Either a single-pole or a two-pole filter may be used to smooth the generated sense voltage. A DC bias is provided to the filter to ensure a positive voltage. The circuit also includes a high-gain, high-impedance amplifier to translate the high impedance voltage of the sensing portion of the circuit to a relatively low impedance voltage for use by an electronic control circuit. In one embodiment, a high-gain emitter-follower amplifier constructed from two bi-polar junction transistors (BJTs) is used. An integrated Darlington configuration may be used, as well as a single BJT having a high gain, and an integrated operational amplifier.

Abstract translation: 提供了一种模拟火焰检测电路，其利用感测火焰的火焰整流方法。 该电路使用AC电压源和分立元件来提供对火焰电流的感测。 可以使用单极或双极滤波器来平滑所产生的感测电压。 向滤波器提供直流偏压，以确保正电压。 该电路还包括高增益高阻抗放大器，以将电路的感测部分的高阻抗电压转换为相对较低的阻抗电压，以供电子控制电路使用。 在一个实施例中，使用由两个双极结晶体管（BJT）构成的高增益射极跟随放大器。 可以使用集成的达林顿配置，以及具有高增益的单个BJT以及集成的运算放大器。