Variable Bandpass Filter

[chi_boy]

I had a layout posted for review, but nobody was interested. I revised it a bit, but it's still pretty much the same. I can post the new one tonight, but it's still not verified.

I also did a layout to attach to a rotary switch to change the filter resistors, but that's not verified either.

Just the same, I'll post it all.

[chi_boy]

Well, for better or worse, these are the file I came up with.  This is still UNVERIFIED!

The switches are supposed to replace the filter resistors to change the cutoff.  I tested this on the breadboard and it worked, but haven't tried it with the rotart switch yet.















 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Group	Name	Value	Quantity
Capacitors	C1	100uF	1
Capacitors	C2	47uF	1
Capacitors	C3, C10	0.1uF	2
Capacitors	C4, C5, C7, C6	0.01uF	4
Capacitors	C8	0.01, 0.1, or 1.0uF	1
Capacitors	C9	1uF	1
Diodes	D1	1N4001	1
IC's	IC1, IC2	TL072	2
Potentiometers	VR1	100K	1
Resistors	R11, R19, R17, R13, R9	100K	5
Resistors	R12, R10, R8	56K	3
Resistors	R16, R14, R18, R15	51K	4
Resistors	R2, R1	47K	2
Resistors	R20, R5	10K	2
Resistors	R21	22K	1
Resistors	R22, R3, R4, R24	1M	4
Resistors	R23	100R	1
Resistors	R7, R6	5.6K	2
Transistors	Q1, Q2	2N5088	2