Hello,I'm working on a prototype device and would like to use this module to charge the battery(LIR2032), for that reason i bought 4 of this modules from you and now i have some qu...
JaneYu 2017-05-30 23:20:57 9 Views6 Replies Hello,
I'm working on a prototype device and would like to use this module to charge the battery(LIR2032), for that reason i bought 4 of this modules from you and now i have some questions for it.
Do you have any more detailed description for that module? Does it include any charging circuit, if yes how to connect it to what battery?
Do you have application example for that WP711B module?
Does this device include an LI-PO battery charging circuit?
best regards
Kai
Hello,
I am using the WP711B module for my prototypes and i am very happy with the results, it just works perfect. My question is now about the other module this company mentions on their webpage. The module is the WP712A and it is the same but round with about 19mm diameter. Can you get your hands on that module? I wrote the company but i get no answer.
JaneYu Hi Kai, pls see my comments above. It simply puts out 5v at up to 300mA. The highest I got out was 200mA. It certainly does not contain a LiPo charge circuit, but these are easily obtained and can be put between the BIWIN and the LiPo. Nb: LiPo charging is a specialist subject and can cause a fire, so be careful!
There are no PDF specs for it. See BIWIN dot COM. In practice, I found it needs no/low load until it starts to pump out 5V at which time it needs a load of at least 75mA (in my tests) or it cuts out. This is what you would expect if it was trying to feed a standard smart watch looking for 5V in a micro USB. Ie: It cuts out when charging is complete. These results vary from Qi charger to charger.
Notes: If the device is not aligned perfectly on a charger (about 7mm off centre for a standard large coil phone charger), it will never produce the 5V -- it cuts out or never starts. Once it is pumping out some current, I found you can move it around a little and watch the voltage drop up to about a volt while trying to maintain approx 100 to 200mA. Move it too far and it will drop about 2V and usually cut out again. So in practice, you will need to think about mechanical alignment. This is because most chargers are big coils (30+ mm) and obviously this is tiny -- straightforward mismatch (which incidentally tends to make the charger run hot trying to compensate for the losses).
JaneYu Robert, thanks for the picture and link.
I will try to test WP711B with module (https://www.dfrobot.com/pro... that I have.
But I'm afraid that I will burn out the module WP711B.
JaneYu Hi Evgeny, that link is not Qi either. Note that what is special about the BIWIN WP711B is that it complies to the Qi standard which means the charger and receiver talk to each other in serial, analysing each other's needs (quite a lot of data is exchanged -- see Qi standard website https://www.wirelesspowerco... .. they even have a Qi Developer Conference complete with lectures etc). It is an "over the top" standard (some call it bloatware) designed for smart phones to save power, reduce radiation and prevent fires from foreign objects on the charger. Ps: Your link is broke -- it is https://www.dfrobot.com/pro...
Like the others here, I am getting NOTHING out of the two I bought. Sometimes these things need a load, so I put a 200 ohm resistor across it (25mA) and 50ohm (100mA). With 2 differing loads and No load (also with 3 different chargers), I get Nothing out. Admittedly both unit's acknowledge the Qi handshake and cause the chargers to go into a charge pattern. But not even a milivolt out. No information except the specs (300mA) and the pic showing polarity. WHAT GIVES? Can someone please advise?
JaneYu Update: They work if (a) you get it closer the the charge coil than most allow and (b) if you put a load on it AFTER it handshakes and BEFORE it cuts out. This would be the sort of load you would expect from a healthy but discharged LiPo.. Ie: allows up to a couple of volts at nil current before a charge current flows as the voltage is increased. However, if you put even only 200 ohms across it from 0V, the thing will cut out and never show a voltage. Ie: It worked a lot better when I took the cover off my JETech universal Qi charger. If it is allowed to put out a couple of volts with no load, it will do so, then it will raise the voltage to 5V. If there is no load for more than a second, it stops again (and again, you will see no voltage with a meter). Seriously guys, someone needs to look at documenting this properly.
