what is the switch for in this circuit??

Hello all,

what are the switches in this circuit? it look like its just there to cut out the noise rejection part of the circuit when the frequency is higher, but what would the reason forthat be? does the noise rejection part affect anything if a clean higher signal freq is coming in? and if i was going to build this to use for low freq could i just omit the switch and have the noise rejection permanently in place?

**broken link removed**

thanks
bonanz

Looks to be that your assumptions are correct. The comparator is only needed when the input source contains alot of noise but i'd leave it in the circuit permanently unless your input is at a very high frequency in which the proprogation delay of the particular comparator would be detrimental. The dotted line running from S1a to S1b tells me that these switches are mehanically connected, so actually theres just one DPDT switch, toss it.