The project is from a Russia customer,we cooperate a smart home PCB system before, and this time they want develop a gas meter project .The Qty is 30K every 3 months.They provided gerber file and BOM list, with some pictures of former type gas meter PCB.
The PCB is used for gas meter, so there are a LCD display and a battery.There are also with some IC.There are more than 50 kinds of components, the value of each kind of component, accuracy is crucial.Any error will cause the product not to work.So we suggest the customer firstly make 5-10 pcs samples to check the function, if the samples work well then continue to make mass production 30K pcs.
It is a 2 layer PCB,TG140,1.6mm board thickness,1oz copper thickness, surface finishing HASL,Solder mask green and Silk print white.Fabricate per IPC-6012 Class 2,punch tooling hole registration tolerance +/-0.005.Conductor width tolerance +/-20%.The fabrication shall be UL approved.The board size is 68mm*66.5mm just like a round.
We checked the BOM list, and try best to use alternative components. As some components could use alternative ones with same specification ,same quality,but low price.Our customer told us they want good quality but also want develop this project not cost a lot. It is a good way to save cost of using the alternative ones.We change manufacturers of connectors,resistors,capacitors,battery holder,and pin headers.The IC we used the same one as BOM listed.Our engineer checked the BOM list carefully, we list all the question and confirm with the customer.Instrumentation projects must have good precision.About the battery, we give a part No. Of it and attached a data sheet let customer to check.The customer didn’t list specification of many pin header,we check the gerber and provide all data sheet to customer to check.It’s a two side solder PCB, so we also must check temperature to avoid damaging some component on the PCB.
The gas meter uses a logical encryption card (referred to as an IC card) as an information carrier. When the system works normally under the monitoring of the voltage monitoring circuit, the control module reads data from the IC card and exchanges data, and the relevant gas quantity information of the gas meter. Information such as the working status is written into the IC card and fed back to the gas sales management system through the IC card. When the gas is used, the control module receives the signal from the acquisition module and performs corresponding measurement processing on the gas quantity information in the table. When the remaining gas volume in the table drops to 0, the control module issues an instruction to close the valve to cut off the gas path. preventing the use. Gas, until the user re-inputs the gas volume into the gas meter, the gas can be restored to achieve prepaid management. When the control module receives a signal such as magnetic field interference, it will issue a valve closing command to shut off the gas path and send the corresponding status information of the gas meter to the LCD display. When the user inserts the IC card, the control module will send the status information. Write the IC card, when the gas is purchased again, the gas sales management system will read the status information in the IC card and save it to the database.
We are making 5pcs samples now. When the samples finished, we will ship them to our customer.They will test the samples.As to check this function is not a simple process.It is a complex system test, and the gas meter is about people's lives and safety. Make sure there are no problems.
- No.13-1 Youquan Road,
- Zhanqian Street, Jinzhou District,
- Dalian, China