| Electronics > Beginners |
| SMD Soldering practice kit instructions |
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| hamster_nz:
--- Quote from: rthorntn on April 04, 2018, 04:34:53 am ---Perfect, thanks, last question D16-D19 what frequency do they flash at? --- End quote --- They flash at the same frequency as the circle of LEDS - 1/2.5 Hz. The interesting thing is the duty cycle. Take another look at that CD4017 waveforms from the data sheet you included a few posts back. It should make it all clear. --- Quote from: rthorntn on April 04, 2018, 06:30:14 am ---Also is D12-D15 purpose to block the flow of current in the reverse direction? Thanks! --- End quote --- If assembled correctly, there is no chance of the emitter on the transistor getting much higher than 0.7V, and even then that will only occur when the diode is forward biased. I really can't imagine any reason for them being there, apart from soldering practice. |
| rthorntn:
Edit: I can get continuity on on side of R48 but not on the other side. Hi All, Please be gentle, my first attempt at SMD soldering, haha, it doesn't work at the end of step 1. Using a Hakko at 320C with 60/40, I'm not adding extra flux. If someone can spare the time please take a look, looking for theories, tips or what I could do to troubleshoot with a DMM? I potentially destroyed something with heat, the components just move around when I get near them with the iron. I accidentally attached U2 (not sure if it matters) I got 20 of these kits so I will keep practicing :) Thanks for looking. Richard |
| hamster_nz:
Hi Richard R50 doesn't look to be attached at both ends. Do you have any 'realy good' tweezers? I find mine invaluable. The are so hard and sharp that they are dangerous :) Here is my process.... 0. Iron about 280. 1. Tin one pad. The quantity of solder on the diode pads loots fine. (If I tin both I can never get the part to sit flush). 2. Place and hold part with tweezers. 3. Solder the tinned pad by just heating it 4. Check, reheat and adjust if needed. 5. Then solder the second pad, using more solder wire. 6. Reheat the first pad till it melts. If the part moves then the solder at the other end hasn't wetted correctly. 7. Solder any other pads (eg transistors, ICs) I still need wick and/or a flux pen on the ICs more often than not.. As they now say in school... Practice makes perfect! |
| hamster_nz:
--- Quote from: rthorntn on May 07, 2018, 07:40:02 am ---Please be gentle, my first attempt at SMD soldering, haha, it doesn't work at the end of step 1. Thanks for looking. Richard --- End quote --- It is only fair that you can chuckle at my soldering too (it is the blind leading the blind). The local shop only has 0.7mm solder, and I always end up with too much on the joint! |
| rthorntn:
Thanks hamster_nz! Could you please post a picture of an entire soldered board so I can use it for reference? I can get continuity on one side of R48 but not on the other side, should I be able to get continuity through a 10K ohm resistor? |
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