hi,
did anyone tested spook? schematics seems to be not in line with gerbers,
f.e. D4/D5 should not be connected with R6 (is it R4 actually?) but also shouldn't be connected with R5
R7 is not connected with C5
TLP062 has output on pin7
probably we have wrong revision of schematics 🙂
There was also some inconsistancy as to what colour LED to use in the input current source. The BOM didn't match the schematic.
Have you built and tested yet? Thanks for doing this BOM, big help to a noob like me.
Question on Infidel BOM: R11 is grouped with 220r parts, but the schematic has it as 22k. I'm ordering both, but curious if that's an error on the BOM or on the schematic - if anyone knows. I think it's BOM oversight and should have been included with R2 and R22, as those are 22k resistors BOM & schematic.
That's the only question from your BOM, so in my book @RickRay , that's a winner! Couple items are backordered, but that's par for the course the last few years, easy enough to find replacements.
Question on Spooky BOM: R7 is shown with 6.8k parts in BOM, but is a 3.9k on schematic? R14/R21 on the BOM are 390r, but schematic shows 620r parts? R24/R29 are 100r 1/8w in BOM, but 82r and 1/2w on schematic, not as concerned with the value as the wattage. Finally R26 is a 1/8w on BOM, but a 1/2w on schematic anyone know which is correct so it doesn't burn?
Now you got me very interested in your Current project???? I was going to use the griddle method I've seen on here a few times, but knowing me I'll just jump in and do it do it by hand, with 10x glasses and 3 overhead spot lights so I don't make any errors... sucks getting old.
That's got me interesed too!. I've used a toaster oven for years but I really should automate it. What controller are you building?
I iagree with you there. i am getting tired of doing this by hand, would be nice to do it all in about 10 minutes, then finish the other parts.
Using a ramp/soak PID controller, an SSR and a thermocouple. My PID only programs in minutes. I need to find one that programs in seconds. I am goin to try this one just running the program about 1 minute longer than the prescribed curve. I think this toaster will ramp up quick enough, but there is only one way to find that out. I am going to place a .063 inch thick plate of aluminum on the tray to set the boards on. That should even out the heating, but again, only one to find out.
I have used the PID contollers on my brewoing set-up and they work perfect. Keep the temp within 1 degree F and don't overshoot. You do need to run the auto-tune a few times to make sure everything adjusts.
I have used the PID contollers on my brewoing set-up and they work perfect. Keep the temp within 1 degree F and don't overshoot. You do need to run the auto-tune a few times to make sure everything adjusts.
R7 should be 3.9K, 6.8K increases the output in the opamp which increases the power dissipation in Q1/Q2.
R14/R21 value should be 390R, this sets the current in the CCS to approx 3-3.3mA through R16/R19.
R24/R29 should be 82R, wattage not that critical as its only dissipating 5mW, so 1/4W is okay.
R26 should be 1/2 Watt.
In addition to this, Spooky has a few design quirks:
- Q1/Q2 will run quiet hot if using a +/-50Vdc power supply (+/-45Vdc at IPS via Output stage). This limits to using the Mini EF3 OPS at max 50Vdc Rails. Running the power supply beyond 50Vdc will most likely cause Q1/Q2 to prematurely fail due to excessive temperatures, this was pointed out at post #329
- The 100K Pot for the VAS current adjustment is exceeding its specifications (max 1mA). If R26 is 47K then the current through the pot is 2.2mA for a VAS current of 4mA. See post #129. The Pot may prematurely fail. Bourns stipulate max 1.5mA for a 100K pot rated at 250mW
- Excessive DC offset may cause the opamp to work a little harder and cause either Q1 or Q2 to become hotter than usual.
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Attached is a draft #2 BOM for the Infidel board. Use at your own risk and please let me know if you find any issues.
Excellent eyes @bullitstang! You were correct R11 was indeed supposed to be 22k, not 220R. Also be advised the actual board is mislabeled on R21 and R22, they should be swapped. Look at @chat72 posts, he is the only one I know of that has completed a build and got it to work.
Out of curiosity, has anyone that has built any of these boards performed a CCS current or VAS current vs temperature sweep. In LTspice the currents vary depending on the type of LED's being used, this causes the downstream currents in the VAS transistors to move around a bit.
If you have built one can you do a test, a rudimentary one will suffice and if so what type of LED's are in use.
If you have built one can you do a test, a rudimentary one will suffice and if so what type of LED's are in use.
hi, i'm redoing layout of SPOOK for THT bjts. if there is an issue with q1/q2 maybe it would be possible to swap them?
it's on an early stage - but maybe someone can chime in and help with layout.
it's on an early stage - but maybe someone can chime in and help with layout.
hi, a question regarding SPOOK
does base voltage for Q16 has to be taken from R22? or maybe it can be taken from separate 820R resistor?
i presume, that if it was done this way it's some kind of voltage divider ... but hey 🙂 i don't know what i'm talking about 🙂
does base voltage for Q16 has to be taken from R22? or maybe it can be taken from separate 820R resistor?
i presume, that if it was done this way it's some kind of voltage divider ... but hey 🙂 i don't know what i'm talking about 🙂
A TO-92 version of the KSA992 / KSC1845 will still run hot, from the datasheet it has a thermal resistance of 250C/Watt, so if the transistor is dissipating 200mW then its temperature is 50C above ambient, example: 200mW x 250C = 50C + 25C(ambient) = 75C.
The Q1/Q2 transistors will need to be in a package that can be mounted to a heatsink.
Yes, its intrinsic to the circuit topology of the input differential (Q3-Q12) and VAS (Q13-Q16) stages.
I think that Q1 and Q2 should use transistors capable of dissipating at least 1W.
Ed
I am currently building a Symasui amplifier, but i am having some issues. At initial startup with no IPS board attached, every thing seems fine using a 60w bulb in series with mains side of the transformer. I have now tried three different IPS boards, including one from Wolverine project. They all give the same result, and just for the sake of it i removed the bulb and tested one channel with IPS to see what happend, and the output resistors ran hot with nice fumes 🙂 Since i have tried several IPS board, its tempting to say i have got something wrong with the output section. I have included the schematic in this post, could any one have a look and tell me if i have dropped the ball somewhere there? All seems fine but...