Print PDF
Favorite
Email
Step 7Solder - Voltage Controlled Oscillator (VCO)
Solder - The Bigger the Glob, the Better the Job
Not really.
So build this however you want. Could be perfboard, make a printed circuit board, go surface mount, whatever.
Voltage Controlled Oscillator - I just went point-to-point. Flatten the pins on the 555 chip and flip it over. Hold it with one of those 3rd hand holders if you have it. I used double back tape to hold it temporarily, even though that's ignoring the ESD (electro static discharge) danger to a CMOS part. Solder parts to it.
Why CMOS? We are controlling the pitch by feeding a voltage into pin 5, the underappreciated Control Input. In the chip there is a string of 3 resistors to make voltage references. Pin 5 lets you yank those voltages around and that changes the pitch. In a normal bipolar 555 the resistors are 5k ohms, but in the CMOS 555 they are 100k ohms. Much easier to yank around.
Not really.
So build this however you want. Could be perfboard, make a printed circuit board, go surface mount, whatever.
Voltage Controlled Oscillator - I just went point-to-point. Flatten the pins on the 555 chip and flip it over. Hold it with one of those 3rd hand holders if you have it. I used double back tape to hold it temporarily, even though that's ignoring the ESD (electro static discharge) danger to a CMOS part. Solder parts to it.
Why CMOS? We are controlling the pitch by feeding a voltage into pin 5, the underappreciated Control Input. In the chip there is a string of 3 resistors to make voltage references. Pin 5 lets you yank those voltages around and that changes the pitch. In a normal bipolar 555 the resistors are 5k ohms, but in the CMOS 555 they are 100k ohms. Much easier to yank around.
| « Previous Step | Download PDFView All Steps | Next Step » |
 |
Add Comment
|
