<https://lh3.googleusercontent.com/-v0bjuN0XQWg/VgMGNJhH7bI/AAAAAAAAAF0/vLSC_u2tz3M/s1600/mc34063_mk15cm1.gif>


The picture seems to be moved, so this is the PS I'm planning to implement 
into my design. Do you think this one is fine for 4x IN-14 and 4x INS-1?
Thanks.

Dana srijeda, 23. rujna 2015. u 20:39:23 UTC+2, korisnik Luka C napisao je:
>
>
> Okay, so I read all the advices and thank you all for explaining the 
> problems with this power supply. Since the board is extremely small and I 
> will be installing it in a very thin housing, I don't really have much 
> space to do modifications on it. So, I'll implement PS in my PCB design and 
> solder its components on it.
> I'd like to know if you could check this PS and see if it should be ok for 
> my clock (4x IN-14 and 4x INS-1 tubes)?
>
> Thanks a lot in advance.
>
>
> <https://lh3.googleusercontent.com/-b9BU5T8kpY4/VgLxiEHdmZI/AAAAAAAAAFk/x7hJ0aVd_dA/s1600/mc34063_mk15cm1.gif>
>
> Dana utorak, 22. rujna 2015. u 21:23:39 UTC+2, korisnik gregebert napisao 
> je:
>>
>> Why not just use a totem-pole pre-driver for the MOSFET ?
>>
>> BTW, this touches on a challenge when designing HV drivers, whether they 
>> are for DC-DC converters or driving cathodes. Most high-voltage NMOS 
>> devices (~400V)  need 5-6 volts for solid gate turn-on, yet logic-levels on 
>> most micro-controllers and FPGAs are only 1.2 to 3.3volts.  That leaves a 
>> few options:
>>
>> 1. Use high-voltage logic, such as 4000-series CMOS, to drive HV NMOS. My 
>> first nixie clock does this.
>>
>> 2. Use NPN drivers; you can easily design constant-current drivers 
>> running from 3.3V. I've used surface-mount devices with 2 NPNs inside, and 
>> they are rated at 250V.
>>
>> 3. Use a level-shifter between your logic and the driver. I'm doing this 
>> on my current design with a HV5530.
>>
>> 4. Find a device with a low-voltage gate. Good luck on this; most 
>> logic-levels NMOS devices only handle 60V or less. If you also want low Rds 
>> (necessary for DC-DC converters), you have even fewer options.
>>
>> 5. Pull-up resistor. Ugghhh... It will work, but you will burn more 
>> power. Could be dangerous for a DC-DC converter if the logic/software 
>> turning off the gate goes haywire, which would lead to large 
>> current/burnout.
>>
>>
>> I advise against relying upon the voltage-drop of the nixie tube to 
>> protect the driver, though this is commonly done with designs using the 
>> 74141. I always select my driver to handle the maximum-possible anode 
>> supply, and add margin above that. I've never had a fried driver, ghosting, 
>> etc. Parasitic capacitance and leakage can stress drivers above their 
>> maximum ratings, which will lead to premature failure.
>>
>

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