Schmitt trigger BJT based another topology - will not run above 1 MHz

175

02:13:15

Here is another topology that looked promising. Its pretty much the standard transistor BJT Schmitt trigger. 

At least in EC it won't go past the 1 MHz warp speed time barrier. 

I dunno if this is an EC thing or the design itself that causes this. 

As ever I seek opinion 

Now, obviously, I invite thee now normal rubbish minded pedophile/ racist/ mind job/ brain clamped rubbish that spouts fourth from our free trial trolls. 

On the other hand, I look for constructive comment from real electric minded personal. 

73

published 8 years ago

eekee

8 years ago

I turned it down to 100kHz, and did not see any hysteresis.

eekee

8 years ago

I put an hour or two into tweaking this, and got a nice crisp output at 1MHz. I think the primary reason was I changed all the 10k resistors to 1k. More current to overcome the transistors' inherent capacitance, I guess. Here's my copy, with copious working notes and some other junk I tried: http://everycircuit.com/circuit/5766466531229696

eekee

8 years ago

My copy now runs fairly well at 7MHz. Reducing resistor values was the main improvement again, but I couldn't just dial them all down this time. Here's a cleaned-up copy without all the working notes... and some last-minute improvements: http://everycircuit.com/circuit/4572569775898624

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