Yes, it is MOST DEFINITELY the problem. The 74HC series are 5 volt chips. If
you connect them to 15 volts they either immediately blow up, or if the
current is limited as it is in this case, they draw what current they can to
the detrement of whatever is going on around them. Make sure you get a
genuine 4000 series chip.
These are MC14051 if made by Motorola or most likely CD4051 if made by
someone else. There will probably be B or something like that after the code.
Never use a 74HC4xxx in any of my designs, unless I specifically give the
full code number. So far the CGS46 is the only board to use one - a 74HC4046.
Ken
Ken Stone sasami@...
Modular Synth PCBs for sale <http://www.blaze.net.au/~sasami/synth/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>
you connect them to 15 volts they either immediately blow up, or if the
current is limited as it is in this case, they draw what current they can to
the detrement of whatever is going on around them. Make sure you get a
genuine 4000 series chip.
These are MC14051 if made by Motorola or most likely CD4051 if made by
someone else. There will probably be B or something like that after the code.
Never use a 74HC4xxx in any of my designs, unless I specifically give the
full code number. So far the CGS46 is the only board to use one - a 74HC4046.
Ken
> Yes! Im using one for the other 4051. It says on it, CD74HC4051E. Is this_______________________________________________________________________
>the problem?
>
>On 2/9/07, sasami@... <sasami@...> wrote:
>>
>> Have you used any 74HCxxxx chips? Something is drawing way too much
>> current.
>>
>> Ken
>>
>>
>> >Ok so here are the voltages,
>> >
>> >pin 7,8: 2.12v (this should read -.6v?)
>> >
>> >pin 16: 14.31v
>> >
>> >pin 3: 1.59v (should this read 0v?)
>> >
>> >I also checked the voltages at the 2.2k resistors located by the power
>> plug
>> >and they are reading, 2.12v and this should be at -.6v correct? How do I
>> get
>> >it to be -.6v? It seems that this is the problem? At the other end of the
>> >resistors it reads -15v. I checked the voltages at the power supply
>> >connection and they are correct.
>> >
>> >thanks for your help Ken
>> >pete
>> >
>>
>>
>
>
>[Non-text portions of this message have been removed]
>
>
>
>The CGS Modular Synth home page: http://www.cgs.synth.net/
>
>Yahoo! Groups Links
>
>
>
>
Ken Stone sasami@...
Modular Synth PCBs for sale <http://www.blaze.net.au/~sasami/synth/>
Australian Miniature Horses & Ponies <http://www.blaze.net.au/~sasami/>