SG8 Pot location

[Faraday88]

one other thing i would do, is add a LED and resistor to the output of the 555, so you can see how fast it is dumping the caps

I have done this too!!very impressive and indicative of how the dump is taking place!
Rgds,
Faraday88.

[claudio]

one other thing i would do, is add a LED and resistor to the output of the 555, so you can see how fast it is dumping the caps

will do !
between the 555 output and R12 (10k) ? what kind of resistor ?

this circuit is more and more similar to the JB "original"...


PCB_PCBetching_20180528100158.pdf

[RS_]

put a 330ohm 1/4W resistor in parallel with the 330ohm that is hooked up to the opto, and the new LED in parallel with the LED in the opto to the Pos rail, then the new LED will operate the same as the LED in the opto....

[claudio]

put a 330ohm 1/4W resistor in parallel with the 330ohm that is hooked up to the opto, and the new LED in parallel with the LED in the opto to the Pos rail, then the new LED will operate the same as the LED in the opto....

I'm a little confused here...
One or two LEDs ?
Am I getting this correctly ?

PCB_PCBetchLED_20180529093326.pdf

[claudio]

If I may slip my 2 cents in here, pins 1 and 2 of your optocoupler go to an infrared (invisible light) LED inside the optocoupler. That's the "other" LED that RS is referring to. You are running a 330 ohm resistor to it. In an optocoupler circuit that I built (for an unrelated application) I added a second red LED (green or amber is OK but white or blue requires a higher voltage and would further complicate things at this point so best stick with red) to tell me when it was on, similar to what RS is suggesting you do here. But I put my second LED in series with the optocoupler pin 2 which would require reducing the 330 ohm resistor to around 150 ohms and no second resistor would be necessary. 10 milliamps (0.010 amps) should be sufficient to operate the optocoupler LED but don't run any lower. That way you will be guaranteed to notice if the optcoupler's internal LED burned out (unlikely but possible and also reassuring) since current will no longer flow through the red LED as well if the optocoupler LED dies since they would be in series.
Sometimes, little details like this extra LED makes troubleshooting so much quicker and easier. And we all like blinking lights.

Thank you Richard,

is this the idea ?

PCB_PCBetchLED2_20180529171440.pdf

[RS_]

That looks good, 10 to 15ma is good for the opto......

now make the short trace to Screw Pad 2 as fat as the rest of the trace.....

[RS_]

Good catch Richard..... Opto pin 4 to the Base of the TIP41, and Pin 5 to the 7812's output.....

Most of the time, the Cap will not discharge down to the Battery voltage level and will have that 2V over the 7812..

I have never seen this version Schematic that Claudio is using.... I had never used a 7812 for that use....

A 10-12V zener diode with resistor and cap will do the trick, but even that is not needed, unless you are killing the base of the TIP41, by charging 24V Battery's

The 4N35 has a Maximum Collector Emitter Voltage: 30 V
H11D1 has a Maximum Collector Emitter Voltage: 300V much better choice when hitting it with Hi V spikes from a SG/SSG.....

[Faraday88]

I hope RS will chime in on this.
It appears to me that you have pin 6 of the 4N35 opto going to the base of the TIP41. Pin 6 of the opto is the opto transistor base, I believe you want to use the opto emitter here (which is pin 4 of the opto) to go to the TIP 41 base. The base connection of the opto output transistor is usually not connected and rarely used for anything. The internal infrared LED is shining infrared light on the base of the opto internal transistor and that is how the opto transistor is turned on.
Did you post the schematic of this circuit on this forum? Are you using the schematic posted by RS on 5-04-18? His H11D1 optocoupler is the same pinout as the 4N35 and RS's schematic shows the H11D1 opto pin 4 going to the base of the BD243C (TIP41).
Claudio and RS, both, are you sure you want to run 12 volts into the 7812? I know that during normal operation the 12 volt battery will be getting charged so it will be running higher than 12 volts but the 7812 normally wants a minimum of 2 volts above its output rating (14 volts input to the 7812). How about a zener (maybe around 10 volts?) and resistor with a capacitor on the output? Here's where it would be nice to have component labels so I will call the battery on the left side of RS's schematic B-1 and the battery on the right side of the schematic B-2. During startup, B-2 voltage is unpredictable, but 10 volts should be expected on many occasions (?)
Claudio, are you breadboarding the finalized version of this circuit before going to etching? Murphy's Law guarantee's that your etched board will NOT work if you don't breadboard the circuit first. (Murphy has been wrong on rare occasion as there are exceptions to every rule.)

Hi Richard,
Yes!! only psychics can defy the Murrphy's Law....Intutive minds are no exception..
Rgds,
Faraday88.

[claudio]

Good catch Richard..... Opto pin 4 to the Base of the TIP41, and Pin 5 to the 7812's output.....

Most of the time, the Cap will not discharge down to the Battery voltage level and will have that 2V over the 7812..

I have never seen this version Schematic that Claudio is using.... I had never used a 7812 for that use....

A 10-12V zener diode with resistor and cap will do the trick, but even that is not needed, unless you are killing the base of the TIP41, by charging 24V Battery's

The 4N35 has a Maximum Collector Emitter Voltage: 30 V
H11D1 has a Maximum Collector Emitter Voltage: 300V much better choice when hitting it with Hi V spikes from a SG/SSG.....

Hallo RS_ and Richard,

thank you again , I am learning..

I'm referring from this schematic coming from the JB and PL Books..


H11D1 will be installed, I just didn't find the opto in the software...
Will use 12V batteries
Of course I will breadboard the circuit, I have all the components ready but unfortunately in this period of the year I do not have much time...

updated circuit
PCB_PCBetchLED2_20180530085545.pdf

[RS_]

still looks like you have the opto output pins wrong, you need to use pins 4 and 5, not 5 and 6

[claudio]

still looks like you have the opto output pins wrong, you need to use pins 4 and 5, not 5 and 6

PCB_PCBetchLED2_20180530163638.pdf

[claudio]

Presuming the left side pin on the PCB is number one on both the TIP41 and the 7812;
the + etch needs to go to the 7812 pin 1, as you already have it.
the 7812 pin 3 needs to go to TIP41 pin 2 and opto pin 5
the 7812 pin 2 needs to go to the - etch
opto pin 4 needs to go to the 2k resistor, as you already have it, and then TIP41 pin 1 (not pin 2).
Labeling the TIP41 and 7812 pins 1, 2, and 3 would be nice. The bce pinout (base, collector, emitter) of the tip41 does not follow the convention that I have been accustomed to over the years with most other transistors being ebc. But that is what the datasheet on Mouser says so that is what I follow. Also notice that the TO-220 package of the 7812 pinout is IGO (input, ground, output) whereas the tiny TO-92 version of the 7812 (LM78L12 rated 100ma output) is OGI.
The 1N4401 and the 1N4403 labels should be 2N4401 and 2N4403 and the yellow outlines should enclose all three pins, not just 2.
The etch under the 555 from pins 4 and 8 can be combined to clean up the design a bit as they both go to the same place.
Most applications of the 555 recommend a 0.01 microfarad capacitor from pin 5 to ground. You have good space available on the PCB and a nearby ground etch so it would be easy to add.

Don't take my word for it, double check against the schematic. And I likely missed something.

Keep up the good work.

Thank you for your specifications, very instructive for me
Breadboarding will prove if it will work
The 7812 I got is the L7812ABV-DG from mouser
Modified the PCB following your wise indications, please confirm the new cap is ok..


PCB_LED3_20180531123106.pdf

[claudio]

The LED etch under the opto looks very tight and is not required to carry much current. You could narrow the LED run to opto pin 2 down to approximately one third of present width and leave the - etch from terminal 6 at present width, then adjust their positions to give equal space on all sides.
The new 10nf cap on the 555 pin 5 is non-polarized so the + label may be eliminated.

thx

PCB_LED3_20180531222751.pdf

[claudio]

I noticed you put labels back on the resistors. Why don't you put 150 (drop the ohm) on R13 and move the R13 label below like all the rest of your resistor labels.
And there are 3 more caps that could use labels.
The 555, H11D1 and 7812 could be labeled U-1, U-2 and U-3. The 2N4403, 2N4401, TIP41 and four IRFP260's would usually be labeled with a Q; Q-1 thru Q-7. Leaving Q-4 through Q-7 labels for the FET's allows you to add or remove FET's to your circuit in the future without adding confusion to your numbering sequence, being it is less likely you would add or remove the 2N4403, 2N4401 or TIP41 for future modifications.
Being there is only one diode you may or may not label it D-1.
I presume this circuit board layout will be mirror imaged for etching since the copper will be on the other side, but for layout purposes it is easier to look at it as you now have it so all thinking doesn't have to go through a reversing process, adding to confusion and error.

done..
I will test on breadboard and if it works will send to manufacture, conductivity is way better on manufactured PCB

thank you

PCB_LED3_20180603090714.pdf

[claudio]

Dear Faraday88, RS_, Richard,

I am finally back to my project, I hope you will be still available to help me…

My SG :
Bike wheel diam. 63,5 cm
21 Magnets 5x2,5x1cm (smaller than indicated on the book but in EU could not find them)
Coil: Teslagenx 7 strand + 1
RPM 314
Amp in 1,4
Amp out 0,6-0,7
Batteries (Primary and Charge) 12V - 45ah
Resistence on impulse 157 Ohm (Potentiometer stil there)

No Capacitor module yet…

I am having difficulties on understanding the right connections for the Cap Module I produced (if it will ever work!).

I post here the images of circuit, PCB and scheme to explain:
When I connected 1 to the neg charging Battery and 2 to the pos it fried the ammeter immediately.
What am I doing wrong ?

Could somebody help please…

thank you
regards
claudio