Need simple 1vdc relay circuit
in [Basics]
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From: Arcadefreaque on 20 Jan 2010 11:32 Okay, admittedly I am not that well versed in electronics. I can solder and follow directions well enough to put together some interesting hacks occasionally, but I'm really a greenie when it comes to certain aspects. I'm trying to find a reasonable way to accomplish turning on and off a device that is powered by about 3.6vdc. The trigger mechanism would be a cell phone's vibration motor's power source (motor disconnected) which outputs somewhere around 1 - 1.3vdc. I started this project by using a simple relay circuit controlled by a serial port of a computer, but now want to move it to the cellular angle - which gives me much lower power output unless I go with some sort of bluetooth serial adaptor (which I'm working on as well). For now though, if anybody has ideas on a simple scenario for a quick switching relay circuit that would work for this scenario, I'd really appreciate the assistance. Thanks af
From: Jamie on 20 Jan 2010 18:36 Arcadefreaque wrote: > Okay, admittedly I am not that well versed in electronics. I can > solder and follow directions well enough to put together some > interesting hacks occasionally, but I'm really a greenie when it comes > to certain aspects. > > I'm trying to find a reasonable way to accomplish turning on and off a > device that is powered by about 3.6vdc. The trigger mechanism would > be a cell phone's vibration motor's power source (motor disconnected) > which outputs somewhere around 1 - 1.3vdc. > > I started this project by using a simple relay circuit controlled by a > serial port of a computer, but now want to move it to the cellular > angle - which gives me much lower power output unless I go with some > sort of bluetooth serial adaptor (which I'm working on as well). For > now though, if anybody has ideas on a simple scenario for a quick > switching relay circuit that would work for this scenario, I'd really > appreciate the assistance. > > Thanks > af Using a basic NPN common emitter mode so that the collector will pull the load to common. The NPN can then pull a higher voltage load like the low side of a relay.. The relay can be supplied with what ever voltage is required up to the rated spec of the NPN. A 220 Ohm with that voltage drive, should be enough to saturate a common 2N2222 type transistor..
From: Tom Biasi on 20 Jan 2010 18:20 "Jamie" <jamie_ka1lpa_not_valid_after_ka1lpa_(a)charter.net> wrote in message news:GaM5n.1223$CM7.102(a)newsfe04.iad... > Arcadefreaque wrote: >> Okay, admittedly I am not that well versed in electronics. I can >> solder and follow directions well enough to put together some >> interesting hacks occasionally, but I'm really a greenie when it comes >> to certain aspects. >> >> I'm trying to find a reasonable way to accomplish turning on and off a >> device that is powered by about 3.6vdc. The trigger mechanism would >> be a cell phone's vibration motor's power source (motor disconnected) >> which outputs somewhere around 1 - 1.3vdc. >> >> I started this project by using a simple relay circuit controlled by a >> serial port of a computer, but now want to move it to the cellular >> angle - which gives me much lower power output unless I go with some >> sort of bluetooth serial adaptor (which I'm working on as well). For >> now though, if anybody has ideas on a simple scenario for a quick >> switching relay circuit that would work for this scenario, I'd really >> appreciate the assistance. >> >> Thanks >> af > Using a basic NPN common emitter mode so that the collector will pull the > load to common. The NPN can then pull a higher voltage load like the low > side of a relay.. The relay can be supplied with what ever voltage is > required up to the rated spec of the NPN. > > A 220 Ohm with that voltage drive, should be enough to saturate > a common 2N2222 type transistor.. > > I second this. Don't forget the back EMF diode across the relay. Tom
From: John Fields on 20 Jan 2010 20:42 On Wed, 20 Jan 2010 18:20:33 -0500, "Tom Biasi" <tombiasi(a)optonline.net> wrote: > > >"Jamie" <jamie_ka1lpa_not_valid_after_ka1lpa_(a)charter.net> wrote in message >news:GaM5n.1223$CM7.102(a)newsfe04.iad... >> Arcadefreaque wrote: >>> Okay, admittedly I am not that well versed in electronics. I can >>> solder and follow directions well enough to put together some >>> interesting hacks occasionally, but I'm really a greenie when it comes >>> to certain aspects. >>> >>> I'm trying to find a reasonable way to accomplish turning on and off a >>> device that is powered by about 3.6vdc. The trigger mechanism would >>> be a cell phone's vibration motor's power source (motor disconnected) >>> which outputs somewhere around 1 - 1.3vdc. --- If you can stand to lose about 0.3V of that 3.6V into the load: (View in Courier) Low side driver: .. +3.6 .. | .. [LOAD] .. | .. C ..1V>--[1K]--B 2N3906 .. E .. | .. GND High side driver: .. +3.6 .. | .. +--------+ .. | | .. [10K] | .. | E .. +------B 2N3906 .. | C .. [1K] | .. | | .. C [LOAD] ...1V>---[10K]---B 2N3906 | .. E | .. | | .. +--------+ .. | .. | .. GND JF
From: John Fields on 21 Jan 2010 19:50
On Wed, 20 Jan 2010 19:42:43 -0600, John Fields <jfields(a)austininstruments.com> wrote: >On Wed, 20 Jan 2010 18:20:33 -0500, "Tom Biasi" <tombiasi(a)optonline.net> >wrote: > >> >> >>"Jamie" <jamie_ka1lpa_not_valid_after_ka1lpa_(a)charter.net> wrote in message >>news:GaM5n.1223$CM7.102(a)newsfe04.iad... >>> Arcadefreaque wrote: >>>> Okay, admittedly I am not that well versed in electronics. I can >>>> solder and follow directions well enough to put together some >>>> interesting hacks occasionally, but I'm really a greenie when it comes >>>> to certain aspects. >>>> >>>> I'm trying to find a reasonable way to accomplish turning on and off a >>>> device that is powered by about 3.6vdc. The trigger mechanism would >>>> be a cell phone's vibration motor's power source (motor disconnected) >>>> which outputs somewhere around 1 - 1.3vdc. > >--- >If you can stand to lose about 0.3V of that 3.6V into the load: (View in >Courier) > > >Low side driver: > >. +3.6 >. | >. [LOAD] >. | >. C >.1V>--[1K]--B 2N3906 >. E >. | >. GND > > >High side driver: > > >. +3.6 >. | >. +--------+ >. | | >. [10K] | >. | E >. +------B 2N3906 >. | C >. [1K] | >. | | >. C [LOAD] >..1V>---[10K]---B 2N3906 | >. E | >. | | >. +--------+ >. | >. | >. GND --- Oops... NPNs should be 2N3904 and the PNP high side load switch could be driven a little harder: Low side driver: .. +3.6 .. | .. [LOAD] .. | .. C ..1V>--[1K]--B 2N3904 .. E .. | .. GND High side driver: .. +3.6 .. | .. +--------+ .. | | .. [10K] | .. | E .. +-[1k]-B 2N3906 .. | C .. | | .. | | .. C [LOAD] ..1V>---[10K]---B 2N3904 | .. E | .. | | .. +--------+ .. | .. GND JF |