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8 Threads found on 555 Delay Circuits
Hello, Circuit as shown in pictures: 130803 Design concept: U0 (not shown) is the output of the door before. After delay 0.5 seconds of NE555, the 3 feet of 74LS74 form rising edge and the 5 feet (U1) output high level, through triode connecting relay (not show
G'day Mate, Bit tricky using passive components only! but depending on how accurate you need the 5 seconds a 555 timer should give reasonable results... remember to use an extended temp range part for automotive use... Follow the design of the mono-stable configuration as shown here... h
From what you describe you need two stages of timers. 1: delay after initial sound begins (or ends?) 2: 'on' time for activating equipment It may be easiest to use a second 555 IC. There's the 556 which contains two 555 in one package. Otherwise if you are willing to experiment, you can use a simple RC combination and find the (...)
use monostable circuit! u can learn more about the 555 timer on thousands of sites on the internet ! and even use/download the program by which u can automatically calculate component values for your required timeout check this :
Hi cfoek, Check for "555-circuits" or 555 timer/555 monostabil multivibrators & even general: triggered timer circuits...., we have such at EdaBoard too... K. Simplest solution is for you: per switch loaded serial RC element of 1uF & ca2.7MOhm to basis of a transistor, their Collector/Emitter has your relay...
You may want to describe the intended circuit operation more clearly. To my opinion it's hard to understand either from the circuits or your description. Generally, introducing a delay in the said range involves capacitors of about 1000 uF. It can be implemented more easily with active parts, either timer circuits with (...)
Single capacitors quite often don't work well as delay circuits .. Maybe you should consider the very popular 555 timer .. something similar to this: Regards, IanP
Hi captainkirksdog, You don't have to worry about triggering a 555 from a CMOS-level logic source as long as you use a CMOS 555 variant, which in fact is a must if you want such long delays: 1-hour. With standard 250 nA BIAS input currents you won't be able to acquire 1 hour delay without special (...)