Chips & Tech.

Tuesday, September 18, 2018

Improving LM339 + "tunable" osc variant

► the tunable osc. as by selecting the RC net-wk

► the tests that lead to (as by what i've tested so far) "improved" v. of LMx93

► 2MHz - TEST (driven from realistic src. 74HC04 -- 1 gate has just about the power required!?)

[Eop]

Friday, September 7, 2018

Couple of osc.-s based on LM339 planned for 2x AA voltage converter

the bad thing with the next is the threshold levels're floating with the supply voltage and specific set of components (makes it difficult to wick the reliable PWM out of it) . . . the concept design → ▼

INPUT below Negative rail - oscillator ▼

[Eop]

Thursday, August 30, 2018

YX8018 ~about "guessing the operation"

→NB←! the following has pretty much nothing to do with the actual chip !!! ←
i just matched some known or guessed data into random simulation substitute

from what we can conclude ::

the device operates best at certain fixed supply voltage (there might be one built in to YX8018)
the best efficiency is occurring below the certain output power = you should not replace the inductor to lesser inductance one without making sure :
a) that there's enough power to drive the inductor (somewhat aided by the 1µF and 5µH caps inductors at the schematic) ,
b) that the inductor won't be driven into saturation
( ↑↑ ← both are primarily indicated by a notable drop in efficiency compared to initial -- however the lesser inductance does, by the idea, give a* higher output power and usually there is some efficiency drop for "trade" to such* )
the onboard inductor in my particular solar lantern has 4Ω series resistance (it might be useful to protect the mosfet from peak power ? from accidental out of cycle re-trigger . . . or provide some voltage regulation for more up to charge battery) , otherwise there's a plenty of room to install a better inductor (such might also cause the over-voltage at the switch drain -- it must be tested out at max input power)

[Eop]

Tuesday, August 28, 2018

Predicate research for using the LED as a photodiode

in prior of doing the following i measured the target Blue LED that did output some millivolts but no nanoamps , then a high efficiency Blue LED that i used for below experiments (← the series array of theses gave pretty much alike data than the single one) . . . then the iR LED parallel array from the (used for . . . ?? pre-clearing the image in) laser printer , it output over 1V and i guess several microamps . . .

. . . all that illuminated from the narrow beam 1W Power LED

the conflicting data (with web) is that when illuminating the LED it outputs fw.-polarity voltage -- e.g. [+] from anode and [-] from cathode * . . . all 3-types of the above without the exception ???

Note* :: no conflict (http://www.ques10.com/p/9330/explain-with-neat-diagram-construction-and-worki-1/) , conflict ( . . . there was a site that actually textually claimed that ? intentionally or not . . . can't re-find it at this time . . . and it was not the only one such . . .)

first couple of web found setups (slightly modified)