A Chinese wireless transmitter insists on long range 4km.
So Enoki tried its range test outdoors. It was similar to Cacazi that Enoki tested before. But the trial condition was not enough, because transmitter power supply voltage was dropping down. However, another description refers to range 300m. 300m may be true.
以前試験した Cacazi と同様のレンジしか得られなかった。別の説明ではレンジ 300m とあるから，これが本当なのだろう。
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Enoki bought the pair of momentary mode at AliExpress.
Enoki confirmed that the transmitter and receiver standby current were 0.8uA at 9V and 7.22 mA at 5V at first. They were measured by DMM PC510.
The working transmitter and receiver current were 80 and 7.25 mA by DMM PC510.
The both boards have no holes to fix. Enoki assembled the transmitter on base board as shown in Photo1.
Referring to PT2262 data sheet, Enoki connected 9V with terminal 12.
Enoki rebuilt the receiver board that Enoki reported it in "Qiachip wireless transmitter review", as shown in Photo2. Enoki also assembled step up DC-DC converter. The converter works at 2V minimum.
Enoki put photo coupler circuit on the UNO this time. Enoki confirmed the transmitter on time 990ms (M250ms) and the interval 29.80s (M5s) by DSO.
UNO has voltage regulator, while 6 NiMH batteries get 7.2V in series. The the transmitter dissipates 180 mA. One allows to use a step up DC-DC converter for 4 batteries, but they will dissipate
Enoki drilled two 7mm diameter holes in 45x9x1 cm wooden plate for M5 bolts. The transmitter base board was fixed on the plate by two 2.1mm wood screws through spacers.
The plastic box contained UNO, battery holder and power supply. It hung by hook. The plate was fixed on 1.8m long steel pipe between brackets through M5 bolts.
The assembly stands as shown in photo5. The antenna of the transmitter stands 2.1m high.
D battery holder as shown in Photo 6. They were fixed through two M3 screws each.
Enoki walked around with the receiver in his hand. The LED lights and holds when the transmitter emits.
All the NiMH batteries were deteriorated and the 2 Mn D batteries were reused.
Photo 7 to 12 shows the limit of each direction. The walking date and time was 2020-04-10 15:05 to 17:25. Table1 shows the range of 4km transmitter. The range was measured by Google Photo GPS and Google Map.
Comparing with Cacazi door bell, the 4km transmitter range is bigger a little. Figure 1 is the same map that Enoki made the previous report.
The 4km transmitter range is 4km nominal. The tiny regulator dropped 1.3V, when the photo coupler turns on. Does the 4km transmitter eat more power?
The specifications describe 180 mA working current.
Although Enoki had confirmed that the tiny AC/DC regulator generated 200 mA before the test, Enoki measured its peak consumption current again as shown in Photo14 and Photo15.
Enoki connected 1Ω current detecting resistor between power and the transmitter GND.
Enoki measured peak current and supply voltage by DSO and DMM PC510.
The transmitter turns on/off power current as shown in Photo16.
Figure 2 shows the measured peak and mean current result. The tiny power supply fed constant peak
130 mA at 7.5V as shown in Photo18, but the peak decreased in 50ms at 9V as shown in Photo17. While 10A power supply DM-310 fed 440 mA.
|G 274||A 261||U 72||J 67||-|
|Z 264||B 250||T 71||K 67||-|
|X 193||C 193||V 55||M 89||R 17|
|Y 242||D 202||-||-||-|
|H 212||E 162||S 54||L 141||-|
|W 202||F 124||-||-||-|
So the transmitter doesn't limit power current, Enoki thinks.
In general, radiation power decreases proportional square of distance inverse
in space. Even if 170 mA increase to 180 mA, The range wont increase sharp.
AA dry battery hardly feeds more than
200 mA, because internal resistance increases for much current. And 6 AA battery holder is expensive.
The Chinese seller at AliExpress where Enoki purchased has referred to the range in Japanese description in the end. The range: 300 - 4000m. If you met conflicted description, select worse description in Chinese store. In this case Enoki learned three times.
© Enoki 2020 April 14