uze6666 wrote:
This illustration is not from me. But I will realise a case in the same style. A laser engraved frontplate is not a problem. We have such engraving machines in the company, where I work. I will order the complete milled and engraved case form the company.
This enclosure with walnut sides looks very nice. Thx for the advice with the aluminium enclosure. My first idea was to buy a aluminium enclosure like this
here is a first suggestion for a minimized SCART based (E)Uzebox...
I was looking at the power supply section and it made me think about my own pcb. To reduce part count, I was thinking about removing the regulator and just feed the board with 5V regulated from those switching wall warts. At first I though that would not be very stable and cause small flickering in the picture, but again Clay Cowgill used just that for the AVCore and the image quality is A1. Is there good reasons to keep the regulator on board?
here is a first suggestion for a minimized SCART based (E)Uzebox...
I was looking at the power supply section and it made me think about my own pcb. To reduce part count, I was thinking about removing the regulator and just feed the board with 5V regulated from those switching wall warts. At first I though that would not be very stable and cause small flickering in the picture, but again Clay Cowgill used just that for the AVCore and the image quality is A1. Is there good reasons to keep the regulator on board?
-Uze
From my power electronics class and projects I worked on in college, my experience tells me to say no. Most commercial switching power supplies are quite good at maintaining their voltage. We built several switching power supplies and flyback converters and they all maintained their voltage very well.
I would recommend of course keeping all of the capacitors on the 5 volt side for decoupling the power supply from the electronics.
Honestly, I was wondering why we had the 9-12 volt power input and voltage regulated it down when I built mine. But based the no complaints or questions about it in the forums, I followed the general schematic.
It's probably so it can use whatever power supply the builder has lying around. 5V switching supplies are great, but you're more likely to have a dumb 9V supply lying around.
uze6666 wrote:
I was looking at the power supply section and it made me think about my own pcb. To reduce part count, I was thinking about removing the regulator and just feed the board with 5V regulated from those switching wall warts. At first I though that would not be very stable and cause small flickering in the picture, but again Clay Cowgill used just that for the AVCore and the image quality is A1. Is there good reasons to keep the regulator on board?
-Uze
In my opinion this is a little bit dangerous, because we use a standard low power socket to connect the power supply. Furthermore often a lot of unused 9V power supplies (from not existing older devices) are available in a household, but not a regulated 5V DC (wall) power supply.
I'm wondering about another point: The controller sockets (and the other connectors too) are not protected against EMC, ESD and damaging by short circuits. No resistors, supressor diodes etc. In our company we have a lot of trouble with this things (damaging of microcontrollers, interferences, noise) and it is impossible to get an CE or similar sign without such protection circuits...
In my opinion this is a little bit dangerous, because we use a standard low power socket to connect the power supply. Furthermore often a lot of unused 9V power supplies (from not existing older devices) are available in a household, but not a regulated 5V DC (wall) power supply.
Yeah, I kinda thought of that too. Moreover, I was concerned about reverse polarity. And can't put a diode because of the voltage dropout. Looks like it's gonna stay like it is.
I'm wondering about another point: The controller sockets (and the other connectors too) are not protected against EMC, ESD and damaging by short circuits. No resistors, supressor diodes etc. In our company we have a lot of trouble with this things (damaging of microcontrollers, interferences, noise) and it is impossible to get an CE or similar sign without such protection circuits...
I aimed at keeping the part count as low as possible. But you point is valid for those who want to sells complete boards. If I recall the AVCore added snubbers to take care of that.