HHc1 PCB Size

[Spark]

Hello guys,

i have here the PDF File HHv1p5 with the Rev.C PCB from the 21. Jan 2004 inside. I have found the PCB gif file in a good quality here at the forum.
But whats the exact size for the single Side PCB(HHc1)?

I want to build the HH from the PDF file is there any error in it?
Or something i must keep my eyes on it by the assembly?

greetings from germany

Tom

[Spark]

Ok i used the pcb dimension from the PDF file(Page 12) and it looks good. So the pcb is 10.2mm wide and 8.8mm long or high. I check the printed pcb with a component and it fits very good on the pcb. So i think i got it. Now time for pcb etching.

Tom

[Qiaozhi]

Ok i used the pcb dimension from the PDF file(Page 12) and it looks good. So the pcb is 10.2mm wide and 8.8mm long or high. I check the printed pcb with a component and it fits very good on the pcb. So i think i got it. Now time for pcb etching.

Tom

I have two RevC 21Jan04 PCBs here, and the actual board size differs by as much as 2mm. Therefore I think it is better to measure the distance between the mounting hole centers. In both cases the distances are 9.7mm and 8.4mm.

[Spark]

Thank you for the mesurment. I think it is not so critical, i check the size with a ic socket and it fits good on the pcb. I have made 2 pcbs one for my wife and one for me today.
The assembly starts today, i hope that all the parts from my order be ok. I read that many people had problems with the 74HC221. One little problem had i found my ordered 7660 is ratet with a max. input voltage from 10,5 volts. Not 12 volt. So i have to reduce the input voltage a little bit for my circuit.

[Qiaozhi]

Thank you for the mesurment. I think it is not so critical, i check the size with a ic socket and it fits good on the pcb. I have made 2 pcbs one for my wife and one for me today.
The assembly starts today, i hope that all the parts from my order be ok. I read that many people had problems with the 74HC221. One little problem had i found my ordered 7660 is ratet with a max. input voltage from 10,5 volts. Not 12 volt. So i have to reduce the input voltage a little bit for my circuit.

Yes - you have to watch that.
The bog standard ICL7660 is rated from 1.5V to 10V, but the ICL7660CPA is rated from 1.5V to 12V.

[Spark]

I search for another 7660 on the market, and change them later. Is it possible to change C19,C20,C21 470nF poly. to ceramic typs? I had forget to order poly. types of that, and on my shop i have only the ceramic ones.
Or is there a problem? Maybe the coupling is bad with the ceramic ones.
What job had this three caps in the circuit?

[Qiaozhi]

I search for another 7660 on the market, and change them later. Is it possible to change C19,C20,C21 470nF poly. to ceramic typs? I had forget to order poly. types of that, and on my shop i have only the ceramic ones.
Or is there a problem? Maybe the coupling is bad with the ceramic ones.
What job had this three caps in the circuit?

Polyester capacitors are for general purpose use, therefore ceramics will be perfectly OK. They are part of the self-adjusting threshold circuit, and are not critical.

[Spark]

Thank you, that helps me much. So i can start to build the circuit right now.

[ODM]

Poly caps will have less loss and voltage sensitivity, but good quality ceramics will still result in a working circuit.

[Spark]

Thanks for the explanation ODM. I have now complete build the power supply and measured all the voltages. The voltage level do fit perfect. And i start to build the clocking circuit.

[Spark]

I have found a few problems and errors in the partlist and the shematic. In the partlist from the pdf R17 and R19 were two times on it. R17 and R19 with 1M value and R17 and R19 with 100k value. What is the right value? Than C10 1000µF is missing on the placement plan. My problem is that i can not adjust R18(100k trim). The pdf says the output from IC6(NE5534) pin 6 should vary from -1.6V to +1,6V with R18. Here starts my problems, i cannot adjust this. The voltage at pin 6 of IC6 is 4.20V DC. So i change the value for R17 and R19 from 1M to 100k without a change. I cannot adjust the voltage. I need a few tipps if anyone has one for me. What can i check next.

[Guzzi]

Had the same problem with a NE5534 it was defect, replace.

[Spark]

I have two of them here but it makes no diffrence. Maybe both of them damaged, but i buy them band new. I have found the C10 place, i read the pdf two times and check the points for the measurments again. All points correct, only the TP4 part does not work right. I have no coil installed only the 680 Ohm R11 is soldered in.

[Spark]

Hello guys,

ok i found the problem. It was my mistake, i forgot to set the jumper wire for Q3 (IRF740). Now with the jumper wire between 2-3(i call it so when you count from the left side of the pcb, 1-2-3) the opamp nulling with R18 (100K) works and the discription from the pdf fits. All measurments are now in the right dimensions. The last problem with the two double values for R17 and R19 in the placmentlist is still there. I looked on the shematic and use 100k for this two resistors, it seems to be it works very good. I read in the forum here that Carl says taht maybe 47k would fit sometimes. I don`t understand at this point the option 1 part and the other impovements for the circuit. I hope this can someone explain me here later.

nice weekend to everyone

Spark