►► the idea behind it was to use a half of 7400 for one "pulse driven RS-JK-trigger" . . . which might be the case if this thing can be opt-/minmized to a lesser component count (total design/build-cost) and made a lot more noise immune (can be operated in realistic env.) - it will start to oscillate if it´s shoulders components won´t match too well (which means almost precisely) -- here i just found the reasonable upper frequency limit for (about 44MHz for inp.-clk.)
the Q0 , Q1 are inter-coupled to get high-fq. readout - with lesser frequency there´s no need to couple them - and originally they were added to confirm the valid readout can be had from K and/or M gates -- so , the fast ver. of this trigger requires the full 7400
1-ce you get customized with these things (OpAmp-s) - they're nifty to use for all sort of tricks -- the below design was chosen due it's adjustability × lesser number of components compared to it´s TTL or CMOS variant
the interesting point to note here is that the КР140УД1408 : LM308 specify their lowermost supply range at ±5V(+10V) : ±2V(+4V) respectivly -- while the voltage buffer/-follower configuration still works with +5V for КР140УД1408 without any fq. compensation ??? here´s the component level model of neither* УД14 nor LM308 OpAmp-s exactly (*also coz "we" don´t know the exact transistors used in the actual thing -- nor does the circuit exactly match neither -- about What? = it's close enough to simulate both (only some 10% of Spice simulations hit the real life - the small alterations to OpAmp model won´t significantly change that figure))
the Regulator :: /̲!̲\̲ this thing seems to perform better than LE50A (STMicroelectronics) , LM78L05ACM (National Semiconductor Corporation) , MC78L05AC (Motorola, Inc.) /̲!̲\̲ when powered by 9V 6LR61 alkaline -- in a sense of IOUT/ΔUOUT . . . . . . . . . history of :: the goal : steady supply for OpAmps powered from Lo-Power battery ►► everything is good as long as you have to implement the current limit . . . so this one has 1 unintentionally "built in" (adjustable by transistor-switch current source) ::
the actual transistor used for switch is ancient 2SD1252A (Panasonic)the custom zeners are random Red-LED + Д9К (apx. 2V + 320mV drop) other BJT-s are 2N3906(-04) but you can use a better ones such as fixed beta 2SA1015 , 2SC1815 ...
!note :: altough theLE50 is labelled as "Very Low Drop" it actually performs worse than 1 of those 78L05-s and the all three b_a_r_e_l_y manage the 150Ω load with reasonable output (4.8 dn2 4.7V) . . .
. . . when the brought regulator does 100Ω with about 10mV output-drop and acts similar to above 3 at about 26Ω with 175mV drop e.g. 4.83V output -- though /̲!̲\̲ it does not have thermal protection and it's current limiting is poorly studied /̲!̲\̲