Generic PCB design guidelines

How repeatedly make good PCB? Many hobbyists faces this issue every time they are prototyping their ideas. Designing the PCB layout (doesn’t matter is it a through hole or surface mount) may be tricky task especially when dealing with dimensions like 0.2mm tracks or 0.5mm surface mount pitches. Laser printer, plotting or other similar transfer technologies can’t deal with such dimensions. After I have tried photographic method of PCB artwork transfer, I don’t even want to touch Iron and laser printer. Using photosensitive laminate and single transparent media I can repeatedly make any number of PCBs. Benefits of using photographic methods are as follows: Transferred artwork is very clear, edges are smooth; Track thickness may be up to 0.2mm or even less with good mask quality, which can be made with good laser printer (usually new one). After printer cartridge refill – printing quality drops down; With one artwork mask I can clone many PCBs; Pay the biggest attention to artwork fabrication. Without good artwork you won’t be able to make good PCB. From My experience I can say, that I always do small mistakes with PCB artworks and I spot them usually after PCB is etched. Devote more time…

Continue reading

PCB Etcher

After UV-80 vas built there was a thought about automatic PCB Etcher with autonomous Heater and bubble machine. This project is hanging in prefinished phase but it does a job. It was used to etch several PCB’s. As this etcher supposed to be used for making PCB’s using photoresitive technology, the controller supposed to control both = the heater of etching tank and heater of developer. As Sensors there are used AD7416 digital temperature sensors. I decided to publish this small project as this is not clear when it will be finished. When it will be, I will update this article. There is a little dirty drawing with dimensions: The dimensions are as follows 215x275x30 exterior. Inner volume is smaller as glass is 4mm thick. So overall volume is less than 1,2 liter. It is ideal volume to use one bag of ammonium persulphate or 250 grams of FeCl3. The glass plates are glued with aqua silicone. Sides are strengthened with aluminum profiles (not necessary if you have skills of gluing aquariums). As you can see it is only manual control 🙂 Thermometer, heater and tank with etchant. Thermometer has scale with more than 50°C as solution shouldn’t exceed this…

Continue reading

Ultraviolet light source UV-80 for PCB exposure

One of more advanced PCB manufacturing methods is exposing laminate copper boards covered by photo resistive layer through mask. Using UV light in manufacturing PCB’s has many benefits according to other methods: you can get thin tracks like 0.2mm. You couldn’t do this by using other home techniques like laser printers or hand artwork; other advantage is that this method gives clean image – smooth edges of PCB tracks. Little bit effort and you can compare results to commercial products. And pf course third benefit is speed and multiple replications of your boards by using the same mask. In this article is described the manufacturing of an automatic ultraviolet light source exposure box.   Parts for UV box Case with organic glass Panel UV lamps ballasts and starters Controller     Case Case is made of 5mm wood board wired with screws.   Making a control panel Control panel consists of two parts:”Power control” and “Automatic control” POWER switch is used to turn on/off power of the UV box. Green LED indicates the ON. MANUAL/AUTOMATIC switch is used to power l the UV lamps manually or automatically. Switches UPSIDE and UNDERSIDE are used to enable upper and lower lamps separately…

Continue reading

AD9288 Protel Footprint

The AD9288 is a dual 8-bit monolithic sampling analog-to-digital converter with on-chip track-and-hold circuits and is optimized for low cost, low power, small size and ease of use. The product operates at a 100 MSPS conversion rate with outstanding dynamic performance over its full operating range. Each channel can be operated independently. The ADC requires only a single 3 V (2.7 V to 3.6 V) power supply and an encode clock for full-performance operation. No external reference or driver components are required for many applications. The digital outputs are TTL/CMOS compatible and a separate output power supply pin supports interfacing with 3.3 V or 2.5 V logic. The encode input is TTL/CMOS compatible and the 8-bit digital outputs can be operated from +3 V (2.5 V to 3.6 V) supplies. User selectable options are available to offer a combination of power down modes, digital data formats and digital data timing schemes. In power-down mode, the digital outputs are driven to a high-impedance state. Fabricated on an advanced CMOS process, the AD9288 is available in a 48-pin surface mount plastic package (7×7 mm, 1.4 mm 48-Pin LQFP) specified over the industrial temperature range (-40°C to +85°C). Pin out designed for 10-bit…

Continue reading

LPC229x protel library

The LPC2292 microcontrollers are based on a 16-bit/32-bit ARM7TDMI-S CPU with real-time emulation and embedded trace support, together with 256 kB of embedded high-speed flash memory. A 128-bit wide memory interface and a unique accelerator architecture enable 32-bit code execution at the maximum clock rate. For critical code size applications, the alternative 16-bit Thumb mode reduces code by more than 30 pct. with minimal performance penalty. With their 144-pin LQFP144 package, low power consumption, various 32-bit timers, 8-channel 10-bit ADC, 2/4 (LPC2292) advanced CAN channels, PWM channels and up to nine external interrupt pins these microcontrollers are particularly suitable for automotive and industrial control applications as well as medical systems and fault-tolerant maintenance buses. The number of available GPIOs ranges from 76 (with external memory) through 112 (single-chip). With a wide range of additional serial communications interfaces, they are also suited for communication gateways and protocol converters as well as many other general-purpose applications. Here you can try my generated LPC2292 protel library. Also this is same Protel library for all LPC229x microcontrollers. LPC2292 protel library

Continue reading