BS2 + neon lamp oscillator = HELP!!!!
Gabezeus
Posts: 3
I'm trying to measure the frequency of a neon lamp oscillator circuit similar to the one below with the neon lamp in series with the capacitor connected at the X's and P10 is connected to the second X:
Vb
/\/\/\/
X
| |---X
|>|
Vss
R C D
Vb = 140V
C = 470pf
R = 10Mohm
D = 5.1V Zener
O = neon lamp (Vx = 65V, Vf = 90V)
This is the code I'm using is:
this reads a time since start and the number of counts onto the debug screen, I can get it to work with switch but once I put my oscillator circuit in i can only get one count. I'm trying to get it to read into Plx-Daq once I can get the basics. The only problem I can think is that the voltage across the zener is 2.45V when the lamp is on, and the current out is 2uA because the operational resistance of the neon is huge. Any ideas why the debug screen only counts one oscillation?
Vb
/\/\/\/
X
| |---X
|>|
Vss
R C D
Vb = 140V
C = 470pf
R = 10Mohm
D = 5.1V Zener
O = neon lamp (Vx = 65V, Vf = 90V)
This is the code I'm using is:
' {$STAMP BS2}
' {$PBASIC 2.5}
counter VAR Word
timer VAR Word
hold VAR Word
counter = 0
timer = 0
hold = 0
DO
PAUSE 1
timer = timer + 1
IF ( IN10 = 1)AND ( hold = 0) THEN
PAUSE 1
counter = counter + 1
hold = 1
ENDIF
IF ( IN10 = 0)THEN
PAUSE 1
timer = timer + 1
hold = 0
ENDIF
DEBUG "Timer is: <", DEC timer,">", CR
hold = 1
DEBUG "Counted: <", DEC counter,">", CR, CR, CR
DEBUG HOME
LOOP UNTIL (counter = 10)
this reads a time since start and the number of counts onto the debug screen, I can get it to work with switch but once I put my oscillator circuit in i can only get one count. I'm trying to get it to read into Plx-Daq once I can get the basics. The only problem I can think is that the voltage across the zener is 2.45V when the lamp is on, and the current out is 2uA because the operational resistance of the neon is huge. Any ideas why the debug screen only counts one oscillation?