Facebook
Google
GitHub
Linkedin
Relay switching circuit
- Thread starter Mellisa_K
- Start date
Thankyou dendad so I shld look for tracking if I buy a dual one?
Do u think this wld be ok not tracking tho? http://m.ebay.com.au/itm/152231690692
That one is not a dual supply.The GND is a connection to the chassis. Neither side of the power supply is connected to the GND but it can be using that terminal. I notice some adverts on Ebay say "Dual" but they are not. They will have +V , 0V and -V terminals and a GND, or 2 x +V and 2 x -V and a GND usually.
Something like this could be one to go for....
http://www.ebay.com.au/itm/LM317-LM...125637?hash=item1c7243bac5:g:oKcAAOSwOyJX~FEH
It is a kit and you will need a transformer and case and maybe meters but it will do ok for most test stuff. Very basic without settable current limit or tracking but would work.
Or even this one if you don't want to put it together.. 2 off these could build a dual supply. Once again, you will need a transformer for each one.
http://www.ebay.com.au/itm/New-LM317-AC-DC-Adjustable-Voltage-Regulator-Step-down-Power-Supply-LED-Module/311723949755?_trksid=p2047675.c100005.m1851&_trkparms=aid=222007&algo=SIC.MBE&ao=2&asc=42399&meid=30a65c466ed1451a8589f799d19418a1&pid=100005&rk=6&rkt=6&sd=122176125637
There are many options. This is just an indication of some cheap ways you can do it.
But later I think. Get your current project up and going first.
Last edited:
Hi AK
sourced all the parts except for HDR2X7-V. Can you give me some more info pls. when I google it i get a blank and the datatsheet site couldnt match it either. Our local electronics components near monopoly retailer Jaycar catalogue also silent.
Also, a question or two abt conventions in circuit diagrams:
- the labelling at the top of the ICs eg U1 2 and 3 what do they have in common. what does U mean? what does P mean Why is a relay K?
- I get the R and the C and earth okay. dont know what VCC (something about voltage somthening current?)
M
Okay thx dendad. It's good advice abt holding off for the moment while I get my project going. I do have a tendency to go off on a tangent particularly when I am following advice in a new field blindly - if I know what I mean. And accumulating shiny things that go ping is appealing.
M
The label at each component on a schematic is called a Reference Designator. In a proper schematic, *each and every* component has a unique one. Without them, discussing the functions or diagnosing problems are cumbersome - saying something is the upper right resistor just doesn't cut it on a schematic with 100 parts.
Here are some standard prefixes:
B - battery
C - capacitor
D - diode
J - jack
K - relay
L - inductor
P = plug
Q - transistor
R - resistor
SW - switch
T - transformer
U - integrated circuit
V - vacuum tube
X - various
Y - crystal
Vcc - Voltage, common collector, generally the positive operating voltage for the circuit. Technically, only for bipolar parts. Since this design uses CMOS parts, it should be Vdd (Voltage, drain). You use this symbol when you don't know what the voltage will be. For these parts it can be anything from 3 V to 18 V, but for the circuit it is the relay operating voltage, 5 V or 12 V.
A very common practice is not to show power and ground connections to ICs. This came out of digital logic schematics in the 60's, where all TTL parts had +5 V and GND connections in the opposite corners. Removing all of the criss-crossing power wires made the schematics much more clear. Because opamps do not have the uniformity that logic parts have, many people show opamp power connections. BTW, C2 and C3 (see how unambiguous that was?) are power supply decoupling capacitors, one for each IC (U3 is a transistor array and doesn't need one). These should be placed as close as possible to each device's power and ground (Vdd and Vss) pins.
Parts with multiple sections, such as a hex inverter or quad opamp, use modifiers. The four opamps in an LM324 would be U1A, U1B, U1C, and U1D. Search for something like 'power supply schematic' or 'function generator circuit' and you will get hundreds of examples under images. Once you get past the overload, you will see patterns and common features, like ground symbols always point down, positive voltage sources are up and negative ones are down, inputs to the left and outputs to the right, etc. These are not hard and fast rules, but conventions that have coalesced over time.
Way before the internet (or even arpanet), I spent all of sophomore English class sitting in the back of the room reading a mentor's entire collection of Popular Electronics. A good schematic is crafted like a story. There is a structure and flow to the information. The primary function of a schematic is to show the *electrical* (not physical) relationships among the components. It often works out that the way the parts are arranged on the page is similar to the way they wind up on a pc board, but forcing the physical arrangement into the schematic usually makes the schematic harder to read. Notice on my schematic that the pin numbers are not in sequence for all parts. They are arranged to make the signal patterns easier to see. This is partly because the ICs do not have the signals pinned in sequential order, but mostly because a schematic with a zillion crossed lines is self-defeating (and painful). In my design library I have seven (7) different symbols for the CD4060, with various locations for the Reset and oscillator pins, different output patterns, etc.; all to make the schematic easier to read. The layout is determined by the physical part characteristics, and is out of your control. No reason to make your life more difficult by pulling that mess into the schematic.
Read and learn.
ak
Here are some standard prefixes:
B - battery
C - capacitor
D - diode
J - jack
K - relay
L - inductor
P = plug
Q - transistor
R - resistor
SW - switch
T - transformer
U - integrated circuit
V - vacuum tube
X - various
Y - crystal
Vcc - Voltage, common collector, generally the positive operating voltage for the circuit. Technically, only for bipolar parts. Since this design uses CMOS parts, it should be Vdd (Voltage, drain). You use this symbol when you don't know what the voltage will be. For these parts it can be anything from 3 V to 18 V, but for the circuit it is the relay operating voltage, 5 V or 12 V.
A very common practice is not to show power and ground connections to ICs. This came out of digital logic schematics in the 60's, where all TTL parts had +5 V and GND connections in the opposite corners. Removing all of the criss-crossing power wires made the schematics much more clear. Because opamps do not have the uniformity that logic parts have, many people show opamp power connections. BTW, C2 and C3 (see how unambiguous that was?) are power supply decoupling capacitors, one for each IC (U3 is a transistor array and doesn't need one). These should be placed as close as possible to each device's power and ground (Vdd and Vss) pins.
Parts with multiple sections, such as a hex inverter or quad opamp, use modifiers. The four opamps in an LM324 would be U1A, U1B, U1C, and U1D. Search for something like 'power supply schematic' or 'function generator circuit' and you will get hundreds of examples under images. Once you get past the overload, you will see patterns and common features, like ground symbols always point down, positive voltage sources are up and negative ones are down, inputs to the left and outputs to the right, etc. These are not hard and fast rules, but conventions that have coalesced over time.
Way before the internet (or even arpanet), I spent all of sophomore English class sitting in the back of the room reading a mentor's entire collection of Popular Electronics. A good schematic is crafted like a story. There is a structure and flow to the information. The primary function of a schematic is to show the *electrical* (not physical) relationships among the components. It often works out that the way the parts are arranged on the page is similar to the way they wind up on a pc board, but forcing the physical arrangement into the schematic usually makes the schematic harder to read. Notice on my schematic that the pin numbers are not in sequence for all parts. They are arranged to make the signal patterns easier to see. This is partly because the ICs do not have the signals pinned in sequential order, but mostly because a schematic with a zillion crossed lines is self-defeating (and painful). In my design library I have seven (7) different symbols for the CD4060, with various locations for the Reset and oscillator pins, different output patterns, etc.; all to make the schematic easier to read. The layout is determined by the physical part characteristics, and is out of your control. No reason to make your life more difficult by pulling that mess into the schematic.
Read and learn.
ak
Last edited:
Well, that rambled on for a while. About P1 -
What to call a part on a schematic varies a lot. Some companies have rules about this, such as showing the complete manufacturer's part number, but generally it is the minimum amount needed to tell the story. For example, the CD4060 is available in three different packages, each with a different letter code. I don't know what you can get, and it doesn't matter to the design, so I don't show that part of the part number. P1 is a generic pin header, 2 rows of 7 pins each. There are hundreds of manufacturers and thousands of parts that will work here. What is important to the design is its function as a place to put a 2-pin programming shunt. A full-blown company schematic would have a text box explaining this, possibly with a company inventory part number for the shunt to use, but there is no need for that level of restriction in a hobby forum.
Search for header or pin header, or even jumper field. If the distributor you are using has a parametric search engine, start with connectors and move down from there.
ak
What to call a part on a schematic varies a lot. Some companies have rules about this, such as showing the complete manufacturer's part number, but generally it is the minimum amount needed to tell the story. For example, the CD4060 is available in three different packages, each with a different letter code. I don't know what you can get, and it doesn't matter to the design, so I don't show that part of the part number. P1 is a generic pin header, 2 rows of 7 pins each. There are hundreds of manufacturers and thousands of parts that will work here. What is important to the design is its function as a place to put a 2-pin programming shunt. A full-blown company schematic would have a text box explaining this, possibly with a company inventory part number for the shunt to use, but there is no need for that level of restriction in a hobby forum.
Search for header or pin header, or even jumper field. If the distributor you are using has a parametric search engine, start with connectors and move down from there.
ak
Please using the complete words, I already saw you used many more abbreviation, the forum does like typing Telix.
You mentioned Jaycar (I think. It is 2AM here and I can't be bothered reading back through the post to check...) as your source of parts.
For terminals, you could use Jaycar HM-310x on the PCB, and HM-312x (x = 2,3,4,6 or 8 indicating number of pins) so the board can be unplugged. These have 5,08mm spacing so will go into every second hole on a protoboard. You may have to drill out the holes a bit. Usually I would use super glue to hold them down as well as the solder.
Another option is Jaycar HM-3130 (2 pin) and HM-3132 (3 pin) and you make as many terminals as you want by sliding them together to make one strip. These are not pluggable but are screw terminals. I use both these types in my boards at various times but not usually from that source as I get them in box lots.
Have you managed to get all the stuff yet?
For terminals, you could use Jaycar HM-310x on the PCB, and HM-312x (x = 2,3,4,6 or 8 indicating number of pins) so the board can be unplugged. These have 5,08mm spacing so will go into every second hole on a protoboard. You may have to drill out the holes a bit. Usually I would use super glue to hold them down as well as the solder.
Another option is Jaycar HM-3130 (2 pin) and HM-3132 (3 pin) and you make as many terminals as you want by sliding them together to make one strip. These are not pluggable but are screw terminals. I use both these types in my boards at various times but not usually from that source as I get them in box lots.
Have you managed to get all the stuff yet?
Yes except for the part I was waiting for clarification from AK on. I can now proceed with the build!!!!
I plan to start next weekend.
I cldnt have gotten this far in a year on my own. And it's less than 3 weeks and I am ready
I am excited and have plans already for another two learning projects connected with this one.
The generosity of your AAC community is humbling.
Yes at least for now. I found my lack of knowledge was an impediment to shopping on eBay but hopefully that will change. Jaycar sales people are the only source of face to face advice I have and they are very nice. Geeky boys. Varying quality of expertise tho. I went to two stores to ask a total of 7 staff what that connector part was and none cld figure it out! But.... There must be someone in their stores with all the smarts I need. Once I find him I will keep him. hehe
I also have learned alot from the jaycar catalogue. It contains advice and look up tables which are helpful
So it's thoughtful of you to help me using the jaycar catalogue. That gives me something concrete as a common language. Thankyou again dendad
Cheers
MK
To all the people who have helped me so far for example:
@AnalogKid @dendad
@MrChips @#12 @ScottW @MaxHeadRoom
A big shout out
Thankyou
And to anyone wanting to get into electronics I am reading this very good kindle book: Electronics For Dummies by Cathleen Shamieh https://g.co/kgs/CkZmDL
She is a great role model for girls.
YGG
@AnalogKid @dendad
@MrChips @#12 @ScottW @MaxHeadRoom
A big shout out
Thankyou
And to anyone wanting to get into electronics I am reading this very good kindle book: Electronics For Dummies by Cathleen Shamieh https://g.co/kgs/CkZmDL
She is a great role model for girls.
YGG
