Your 16 segment tester needs an Oscillator! Digital numbers-Part13

Tell Hans his 3 digit marvel is still THE tool to use!
It took five minutes to hook up the 555 astable circuit, making a variable oscillator for low frequencies.
I’ll deal more with the old LM555 - and the newer one ZSCT1555 - in another video. Now I just wanted to get the project done. So, short reminder about the calculation of period/frequency:
-In all 555 specs you find the formula for the signal period as
P=0.693 (R1 + 2xR2) x C1.
Given the tolerances of the resistors, you won’t be wrong though if you approximate P≈0.7(R1 + 2xR2) x C1
Ex; if you turn the potentiometer to 0Ω, R1=R2=10KΩ and C1=4.7µF.
So P=0.7 x 0.03 x 4.7 ≈0.1sec respectively the frequency F=1/P=10Hz.
When the pot. is at minimum, the output is oscillating approx. 10 times/sec, and as you turn the pot. the frequency goes slower and slower.
For the purpose of watching the 16 seg plus the dp when checking your display, a higher frequency than 10Hz won’t give you any advantage.
Good news: if you want to save a bit of time when calculating the period or frequency of the 555 oscillator, an on-line calculator is available here:
www.555-timer-...
I put on google drive in the “16_Seg_Display” folder both diagram versions. They look similar to the previous ones, but I added the oscillator and the toggle switch.
- For Common Cathode, the file “CC_16SEG_display_Count_17_plus_Oscillator.pdf”
- For Common Anode, the file “CA_16SEG_display_Count_17_plus_Oscillator.pdf”
The link:
drive.google.c...
If there is still any misunderstanding, please let me know in a comment.
CU soon and thanks for watching!