Can I use my C64 PSU for SEQV4 too

MIDIbox SEQ
1

Hello,

 

i want to use the 5V DC pinout of my C64 PSU to supply the SEQV4. So i want connect the 5V directly to J2 (with C8 mounted to J2 (all in front to J1 left out)).

 

Could be the LF33 in this circuit too hot (?), because the CPU delivers max 1A - or should it work fine?

 

Greets,

rio

2

The current rating (1A) is a maximum rating. It simply says the PSU is capable of delivering up to 1A. The midibox will only draw as much current as it needs.

 

The heat dissipated by the voltage regulator only depends on the actual current drawn and the voltage difference between input (5V in this case) and the output (3.3V in this case).

3

So it fits for my needs?

 

Greets,rio

4

Sure.  I recommend you add a SPDT switch with one leg connected to J1, the middle pin to J2, and the other leg to your PSU.  That way you can easily switch between external power or USB power.  Handy to have and will prevent you from using both at once accidently

5

Yes a c64 PSU works on my SEQV4 as well.  USB power depends on the current consumption of the LCD displays. Computer ports mostly supply only 500mA.

6

Sure.  I recommend you add a SPDT switch with one leg connected to J1, the middle pin to J2, and the other leg to your PSU.  That way you can easily switch between external power or USB power.  Handy to have and will prevent you from using both at once accidently

 

So I don’t understand what I have to connect, when I want to use USB power. Does it need to connect to PSU-Circuit [J2 –> 3,3] too (as J2 INput?) or is it not necessary? And if yes, how I have to connect it correct, if I want to use my C64 PSU as a secondary supply. Your decription for the connection confused me, because I don’t know, which way the 5V-USB Power have to go :smiley:

 

Greets, rio

7

Hi Rio,

what Altitude mean is that you can also add a SPDT switch (Single pole, double throw. See picture)

to toggle between USB and PSU power.

This would also prevent you from using both at once accidently.

post-4098-0-70416600-1371691254.jpg
post-4098-0-70416600-1371691254.jpg580×277 15.5 KB

Best regards

Marxon

8

ah ok, now i got it :wink: Thanks.

9

Rio: Why?  The C64 power supply is a piece of shit.  Use a cheap 5V switching wall wart that will be much smaller, will run cooler and be much more reliable.

10

+1

 

There is no analog side here so the cheapest, crappy, cell phone charger will be plenty.

 

in fact, all you need is a cell charger + a USB B connector and you are done the PSU for the SEQ