Features, Applications A merged combination of bipolar and MOS technology gives these devices an interface flexibility beyond the reach of standard logic buffers and power driver arrays. E-shop menu Ycna menu Searching Cart. Proceed to wholesale Login Registration Shopping cart 0. V to VDD 0. Watch the availability change.
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Section 1: General Preamp Questions: Q1. Can I build one? This preamp is not intended to be a "kit"; rather the information presented here is to help, inspire and guide people who might be planning their own project.
PCB layouts, the parts list and source code are not available. For this and other reasons, I have no plans to release the layouts.
The source code is not available. For those willing to put in some effort, this should help considerably. Section 2: Component questions and sourcing information: 2.
It features extruded front and rear panels which results in no visible fixings on the front panel. The top and bottom panels are made from 1. You can buy the case from a number of suppliers, including RS and Electrospeed. It has an indicator in the form of a deep recess cut into the knob. In the end, I gave up trying to find a reasonably-priced off-the-shelf control knob that fitted the bill, and decided to use the knob I already had. To remove the pointer, I simply filled the recess with car-body filler!
Next, I finely sanded it with grit wet-and-dry emery cloth to remove the brushed effect, and spray-painted it using the same process as the front panel see below. You buy the switch body and caps separately. The latest Farnell catalogue shows a range of new accessories and styles for these switches - well worth a look Check here for more info These are signal relays that have the standard BT footprint, so there should be no problems obtaining equivalents in the future if necessary.
You can read more about these relays on the NEC Tokin website. Luckily, Farnell now stock them - part number DIL package. I got the two I used from Allegro as samples.
It took countless emails to get my examples.. To assemble them, I just used a small vice to clamp the two halves together, using thick card to protect the plastic from the rough jaws of the vice. Mark across the width of the ribbon cable using an engineering square to ensure the connectors are at exact right-angles to the cable Farnell stock them, amongst others.
Electrolytic capacitors are a necessary evil, so make sure you fit decent ones! Axial polystyrene are the normal choice here, but they are physically rather large. This is possible because of the optical nature of operation - it works just like the sensors in a mouse, there are no contacts to wear out. There are cheaper options here - contacting encoders typically cost less than a tenth of the price.
However, these need de-bouncing, either in hardware or software. They also "feel" cheaper when operated. Personally, I felt the project was worth the expense! Section 3: Construction questions Q3. The openings in the front panel were done for me. Use of a milling machine resulted in a perfect display window opening, and ensured that all the buttons were in a perfectly straight line.
Thanks are due to Malcolm Rowney for that! The perspex display window was hard work. It would have been easy to just mount the perspex behind the opening in the front panel, but this was cheating!
I started by cutting a piece of perspex to roughly the right shape, and gradually filed and sanded it until it fitted. Making the radiused corners fit exactly with the machined front panel was hard work, but the final results were quite good. It is a good friction-fit, and is perfectly flush with the front panel. I was unsure about the best plan, and for a long time considered removing all the paint and going with a silver front panel. Eventually I decided to try a paint finish, and reached for an old tin of Halfords gloss-black paint intended for car bodywork After lots of very thin coats, the result was a heavily textured matt finish.
I liked this, and decided it would probably do, despite the texture being rather too heavy. But, rather than stopping there, I wondered what would happen if I put some more paint on Unfortunately it started to look like the shiny black gloss finish that you might expect Once the paint had hardened, I wet-sanded it using grit wet-and-dry emery cloth.
This smoothed out the rough texture and left a dark-grey matt finish. Then, applying a few more very light coats resulted in a matt-black, lightly textured finish that was similar to before, but much better quality This was a learning-curve for me, but was good fun. I will definitely try this technique again! The front panel labels are rub-down transfers that came from Maplin. I was using some old stocks.
This was extremely time-consuming - it took all afternoon to label 12 items! I tried to get everything level and evenly spaced, and the results are ok. While not as good as a professionally produced product, the results are much better than my previous attempts. Section 4: Design questions Q4. The 12V trigger outputs are the main reason for having a 12V rail in the control circuit. These are capable of sourcing reasonable currents, so it made sense to regard the 12V rail as the main source of power.
So, the next consideration is the power dissipation in the 5V regulator. The VFD takes almost all of the power here. Using 5V relays would have needlessly increased the dissipation in the 5V regulator. Especially as 5V versions of the relays would consume rather more current Your mileage may vary - there are no fixed rules This is a fair question. But, they take up more space, and this was important in my application. To help with space I used a surface-mounted 74HC - this obviously saved having to drill the extra holes for it!
This FAQ was last updated on September 28th, Part numbers and prices were updated from the relevant websites. Go to page:.
Section 1: General Preamp Questions: Q1. Can I build one? This preamp is not intended to be a "kit"; rather the information presented here is to help, inspire and guide people who might be planning their own project. PCB layouts, the parts list and source code are not available. For this and other reasons, I have no plans to release the layouts.