Hey all,

I am doing a project in which I want to make a query to a webpage every ~10 secs, running on battery and solar power, which should I choose? the sim 900 (over seeedstudio's shield) or the quectel M95 using probably click gsm2 adapter.

price is not the issue, power consumption is, and should be the lowest as possible.

also, right now I am using sim 900, what I do is I "set up" a connection and afterwards just send a CIP command after every 10 seconds or so. do you think it is possible to save some power with sleep mode or will it reset my modem and I will have to connect to the network again?

thanks in advance,

Hello, I am doing a project and I want the user to be able to connect about 12X3 wires (12 wires, each wire has 3 internal wires)
in each wire there are 3 wires, red white and black when all the whites should but shorted and all the blacks should be shorted,

What is the best way for me to connect it? I have a friend with a 3D printer so I thought about making an arduino box which will have the terminals (with screws) in them and then connect it to the arduino board (my own PCB) with some sort of cable, the cable should be able to transfer up to 0.5A for short bursts (100mS).

any suggestions?

thanks.

Hello
Im searching for either a short or thin 4700uf capacitor formy project, does anyone have any recomendations?

[need]

but do you really think I need to do that?

My question is how much would it heat and do you think it might cause any problems.

I want to have my arduino mega connect to the upcoming shield seeeduino gprs shield V2, so I do need (I guess) a pretty large current at some times (broadcast).

The h-bridge was perfect, although it needs only 1 pulse, 100ms with 12v battery, also the 4700 capacitor you offered is working perfectly.

thanks a bunch for all of the help.

Hello,

I've seen the arduino mega max voltage is 12v, I have a 12v acid battery, obviously it give about 12.6v, for best performance (I dont want any heating issues) should I add a 12v voltage regulator or is the 12.6~13v not really an issue?

thanks.

Hey guys,

I made the circuit as was shown here (via fritzing) but the resistors burn.

what Watt should I use? I used 0.5 watt (smd resistors) but I think I got too much current and burned them and the pnp.

thanks.

Thats what I thought,

thanks for the quick reply.

Hello, I have DG408 (http://datasheets.maximintegrated.com/en/ds/DG408-DG409.pdf)

and it says in the following scheme that there is V+, V- and gnd, what does V- stands for?



thanks in advance,

When you talk and design mosfet you dont usually care about the Iin that is charging the gate, although the current that is used to charge it does grow with the Vgate and the Vgate affects the current that flows in the channel itself, it depends on the Vds and the Vgs and it depends if the MOSFET is on saturation or active,

But lets not get into this right now, as this is not the main issue here,

You think that I can just use N channel mosfet connected to demux (so I'd use only 3 outputs to control 8 transistors) in order to pass this..

this is interesting and I haven't thought about that before.. that is actually a pretty good Idea..

thanks.

Well, how can it not? in every MOSFET there is no relation what so ever between the current that is charging the Vgate and the Vdrain-source that is conducting the current to the Vout - as in inverter or any OR or AND gate for that matter.

I know that 600ma isn't a low current, I need it for 2 different tasks, I should have been more clear on that.

for the first one (low current) the DG408 will work, and for the second one I want to latch solenoids (for irrigation).

DG408
http://www.maximintegrated.com/datasheet/index.mvp/id/1003/t/al
DG401, 403, 405
http://www.maximintegrated.com/datasheet/index.mvp/id/1001/t/al

the DG408 seems good but the problem is that the peak current is only 100mA, I think I need something more like 500-600.

Actually I think the SPST is perfect, but I could only find 4 channel and 16 channel, do you happen to know the name of the 8 channel?

I think that the DG406 would do the job, what is the highest current this chip can transfer? (I am talking about Iin) (Is Iin equal to Iout?)

I need that Iin should be equal to Iout, the thing about mux is that Iin has nothing to do with Iout, right?

btw, I am using regulated 9V for the voltage,

thanks.