Thursday, November 26, 2015

an Op-Amps based "Proximity detector" + alternate sine generator

my 1-st concept of proximity detector ::

too many components for flame (color temperature (rainbow)) Christmas lights ::


B4:A4:Y4:X4 -- Red:Green:Blue:Red (!!! a color for the Flame effect -- not generated by this circuit . . .)

using switching and level hold the number of chains reduces to one -- it still might be more practical to use AD and DA converters with digital function generators (?EEPROM) , level hold switced output to gain the voltage 2 color effect of your like ... or use 4 differently biased optos or use a fine adjusted PNP NPN chain (cost efficient) , e.c. . . .

the varying color predecessor of the previous -- an alternative sine generator ::

drawing (supposedly) only 125µA from the 5V source


Tuesday, November 10, 2015

alternate for gas discharge indicator

((fuck this blogger *editor is slow 2day . . . ))

so about :: i've made (now a total) 3 circuits that use active pre-load - all have failed due a different reasons

(i) using ~250V electrolytic capacitors in series with incandescent lamps -- the ´lytes exploded !!! (trivia) -- however it took them 1.5d (some 36h) to heat up -- later i just added more incandescents to fill the voltage gap

(ii) using ceramic capacitor before Russian Lim.?700V full-bridge . . . that actually has a std. leak - e.g. if [+][–] terminals are not connected the –[L]] –– [[~] Bridge [~]] –– [[]Load[]]––2 [[N] – connection provides enough AC for 25W incandescent as a Load to glow near it´s max brightness !!! --- everything worked correctly at nominal !!average!! values (measured by analog multimeter) but the LED and 1BJT failed after 1.5y (apx.13000h) ???

(iii) using 15nF as "200kΩ" pre-load to 60V neon lamp caused the neon´ to relatively fast dim down and collect eighter C or metal film to it´s inner surface causing more dimming (service apx.1500 + ? h)  . . .

. . . so i replaced it with this ::

( it´d make sense to set at least 1 fuse close to [L] or (2-nd near [N]) terminal -- this circuit relies on 10A line protection -- i can't predict how warm the (250mW) 100 ohm limit´ll get in continuous op. and what results if it does heat up . . . )         Update/About -- (so far it does not give out any smoke) but one LED is brighter the other one -- is either the asymmetry of DB3 , a bad selection of capacitor values/ratios -- or a combination of both (some of it can be adjusted by discharge resistors , charge storage cap.-s) . . .

((the Blogger* didn´t crash so far !!! . . .))


Friday, November 6, 2015

Couple of OpAmp experiments

FF(fixed frequency design) apx.~50Hz 3-ph ((another) alternate (for a)) Sine generator

V2F experiment (poor -- attempting to grasp some principles)


Tuesday, November 3, 2015

Couple of new CCS tested

b) the LT1112 reads " ... Picoamp Input" ((i wonder what they mean by that)) anyway it's used here (not as initially planned)

a) almost no change to something already multiple tested but still new

a) compared with oldies ::