Electronics

3 comments

Rate

Alexander.An Participant Join Date: Jun 2012 Location: Tamilnadu, India Posts: 1	Electronics 06/21/2012 1:39 AM
	I'm in need of a simple circuit which can out put a pulse(positve going) @ the arrival of 22v0lt DC and another(negative going) @ the ceasure of that voltage to trigger 4098BE based timers operating @ 9 volts DC. The time of the presense of that 22volt will be around30 secs to 3 mins. Thanks in advance. Alexander.An
	Register to Reply

Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

These comments received enough positive votes to make them "good answers".

PWSlack Guru Join Date: Jan 2007 Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain. Kettle's on. Posts: 32175 Good Answers: 839	#1 Re: Electronics 06/21/2012 4:17 AM
	How about a 24VDC electromagnetic relay? __________________ "Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
	Register to Reply

G.K. Guru Join Date: Mar 2007 Location: Greece / Athens Posts: 722 Good Answers: 28	#2 Re: Electronics 06/22/2012 5:07 AM
	The following schematic, that I made, shows how you could do such a thing. You can further manipulate these two separate pulses as you wish. E.g. you can use 'Smitt trigger' gates in order to make these pulses more rectanular. Furthermore, you can invert the Out2 (i.e. 'negative going' pulse). The zener (on the input) must be 9V (in order to limit the 22V input down to 9V).The gates must be CMOS (in order to be supplied with 9V). __________________ George
	Register to Reply Good Answer (Score 2)

ci139 Guru Join Date: Feb 2012 Posts: 595	#3 In reply to #2 Re: Electronics 06/23/2012 12:12 PM
	(nothing to do - but read this forum - well it's a scheduled "must") the capacitors have what initial charge the idle(standby) current is ... , the idle OUT is ... THE PULSES ARE BOTH POSITIVE _\|_ _\|_ not _\|_ ¯\|¯ as expected is the 9V ±9V or ±4.5V or the idle level should be 0 or +4.5V 22V net > [detect] > 1? / 2? terminals > 9V net __________________ ci139
	Register to Reply

These comments received enough positive votes to make them "good answers".

Copy to Clipboard

ci139 (1); G.K. (1); PWSlack (1)

	Got Something to Say?
	Ask a Question Start a Discussion

	Search this Forum
	Communications & Electronics: Go

	Aerospace
	BioMech & BioMed
	Chemical & Material Science
	Civil Engineering
	Communications & Electronics
	Education and Engineering Careers
	Electrical Engineering
	General Discussion
	Instrumentation
	Manufacturing
	Mechanical Engineering
	New Technologies & Research
	Software & Programming
	Sustainable Engineering
	Transportation

	Site Directories
	Forum Directory Blog Directory User Group Directory RSS Feeds CR4 Rules of Conduct CR4 FAQ Site Glossary Who's Online (76 right now) Show Members