Waveform amplitude decreases, had to field use voltage comparator done, or the same board this time, but is in
Different debugging field to solve different problems, the phenomenon of customer feedback in the indoor equipment can be very good implementation is based on
Infrared sensor drop. monitoring, but near the ring-bearer outdoor outdoor equipment installed will malfunction during the day
As shown in the above, according to the customer feedback, first verified at left and right in the light of the different environment to do
The flood, E as the infrared emission, R for infrared receiving, use LOTO instruments USB oscilloscope
Line OSC802 迚 waveform check, really about two figure, under different light measured by infrared sensor waveform has great
Different
Above, A (near the ring-bearer outdoor outdoor) on behalf of the sun on the illuminate of infrared receiving sensor,
B on behalf of the launchPlate on the infrared emission of infrared receiving sensor head of irradiation, OSC802 collected waveform display, because A according to
Shoot, the superimposed on the B radiation produced by pulse waveform figure C in dc component,
The figure below describes the basic principle of the problems
D is launch board generated waveform, is our last article introduced and meet expectations, C is unexpected,
Light wave, due to the presence of the C, lead to actual waveform from D to E, destroyed the original system
Judgment conditions,
And also unable to change the simple judgment conditions to circumvent this problem, because C waveform in the light of the different
Are different amplitude under the influence of strength, from 0 v in the dark environment can change to the 4 v, outdoor light strong
Feeling 冴, enough to drown out launch plate to infrared pulse signal
Solve the sun strong environment there are many methods for infrared emission plate interference, for transmitting load
Wave, in order to distinguish between a sunlight or tube light, ring is in a particular frequency of infrared transmitting tube to exclude the sun
Interference, such as ring-bearer and hood ring-bearer polaroid, here I adopted the practice of quick and easy, using capacitance
Tandem 迚 circuit to remove the dc interference produced sunlight, get to the pulse signal of infrared transmitting tube after
Using output voltage comparator plastic,
Comparator front ends a resistor for isolation condenser C55 to implement the idea, capacitance value is different, the same
The effect of different light environment:
Finally choose C55 0.1 uF capacitance, problem solving,
Also need to constantly improve hardware circuit design, design and laboratory sample stage and the mature product of
Have larger distance between, met a lot of field application situation 冴 had never expected beforehand, many senior engineers rely on abundant
Rich experience to avoid detours, around the pit on the road, we experience is not enough, can only rely on problems actively
Active move ideas to solve the problem, slowly we will also accumulate the rich experience and purpose and significance of my article
Is here, a short record text is not enough to bring read engineer exact and explicit knowledge, but in
To some extent, reveals a little experience, a little ideas of dry goods, the hope can help you,