Buying and storing electronic components.
Irrespective of a projects complexity, they all require parts, and this means shopping !!
Now, you can “recover” parts from old equipment and I’ll cover this in a separate article, but for now were just going to look at purchasing new parts.
In the “good-ol-days”, a shopping expedition meant wandering into the local electronics supplier, chatting with the usually very helpful and knowledgeable staff and walking out with handfuls of goodies. Its an unfortunate fact that these days you will be hard pressed to find an electronics store that actually sells electronic components, and even if you do, the chances are the staff won’t know the difference between a capacitor and a resistor and probably won’t have what you require in stock anyway.
Now, you can “recover” parts from old equipment and I’ll cover this in a separate article, but for now were just going to look at purchasing new parts.
In the “good-ol-days”, a shopping expedition meant wandering into the local electronics supplier, chatting with the usually very helpful and knowledgeable staff and walking out with handfuls of goodies. Its an unfortunate fact that these days you will be hard pressed to find an electronics store that actually sells electronic components, and even if you do, the chances are the staff won’t know the difference between a capacitor and a resistor and probably won’t have what you require in stock anyway.
The internet is your salvation.
There is a vast inventory of parts available, even to the hobbyist, and it would be impossible for a store to stock even a fraction of this inventory but lucky for us, there are many on-line sources that are only too happy to supply individuals with what they need.
A word of caution.
Believe it or not, there are unscrupulous people around selling fake electronic components. These components can be parts that the original manufacturer rejected during their quality control checks, branded as being a higher specification than they really are (and these can be just darn right dangerous) or possibly even stolen. What all this means is that you need to be carful where you shop.
You are unlikely to find sub-standard parts from a reputable supplier; and if you do, they will usually replace them immediately. You do need to be carful when using on-line auction sites and especially when buying electronic parts from certain countries. Use your common sense and be carful.
You are unlikely to find sub-standard parts from a reputable supplier; and if you do, they will usually replace them immediately. You do need to be carful when using on-line auction sites and especially when buying electronic parts from certain countries. Use your common sense and be carful.
Shop around.
Shopping around is “always” a good idea when looking for parts but you need to look at the big picture. In the UK the big three suppliers will offer you free delivery if you spend over a certain amount with them (that figure is usually around £30), so it’s pointless to buy a part from one supplier to save a couple of pence, only to then end up with a £5 delivery charge.
Remember that you are probably going to be charged some sort of sales TAX or VAT on your final total as well.
As hobbyists, price is always going to be an issue, and the cheaper we can source our parts, the further our budget goes and the more parts we can buy. In the UK, some of the bigger suppliers tend to be dearer than others, but their range also tends to be larger. But, there are often exceptions to the rule.
After many years of buying parts, you tend to get a "feel" for what a part could cost. If it's too cheap, I always make sure that the part I'm looking at is actually what I expect. Connectors are a classic here; Molex for example. You buy some nice cheap connectors only to find that they don't come with the crimp pins.. and these are only available in large multiple quantities and are really expensive. The 10p 5-way shell you just bought is actually going to cost you another £20 if you want the pins to fit it.
Remember that you are probably going to be charged some sort of sales TAX or VAT on your final total as well.
As hobbyists, price is always going to be an issue, and the cheaper we can source our parts, the further our budget goes and the more parts we can buy. In the UK, some of the bigger suppliers tend to be dearer than others, but their range also tends to be larger. But, there are often exceptions to the rule.
After many years of buying parts, you tend to get a "feel" for what a part could cost. If it's too cheap, I always make sure that the part I'm looking at is actually what I expect. Connectors are a classic here; Molex for example. You buy some nice cheap connectors only to find that they don't come with the crimp pins.. and these are only available in large multiple quantities and are really expensive. The 10p 5-way shell you just bought is actually going to cost you another £20 if you want the pins to fit it.
Stocking up.
Now when dealing with component suppliers, it’s often the case that the larger the quantity of a component you buy, the less you will pay which is very handy. As well as thinking about your current project requirements when shopping, you should also give a little thought to your possible future electronic parts requirements. Some components are the “bread & butter” of project construction; transistors, resistors, capacitors and LED’s of all values, shapes and sizes will always come in handy, and even the most carful and diligent constructor will make mistakes meaning you are bound to experience the odd “blue smoke” moment from time to time, so it pays to have spares !!
You can't put the magic smoke back into a component once you've let it out !!
It’s also worth remembering that except for batteries, your electronic components have an almost unlimited shelf life if stored in a cool dry environment. The only possible exception to this rule are capacitors as they often have a type of oil inside and this can dry-out over extended periods of time, and UV sensitive PCB laminate and associated processing chemicals. The good news is that for modern electronics and unless you are going to be making lots of PSU (Power Supply Units), you probably won’t need to have many large value capacitors kicking around, and these are the types that tend to dry out over time, and when I say over time, I means years, not months so there’s little excuse for not stocking up on components if you get the opportunity.
You can't put the magic smoke back into a component once you've let it out !!
It’s also worth remembering that except for batteries, your electronic components have an almost unlimited shelf life if stored in a cool dry environment. The only possible exception to this rule are capacitors as they often have a type of oil inside and this can dry-out over extended periods of time, and UV sensitive PCB laminate and associated processing chemicals. The good news is that for modern electronics and unless you are going to be making lots of PSU (Power Supply Units), you probably won’t need to have many large value capacitors kicking around, and these are the types that tend to dry out over time, and when I say over time, I means years, not months so there’s little excuse for not stocking up on components if you get the opportunity.
Keep a shopping list.
As you build projects, you will use your component stocks or realise that it would be handy to have certain parts “in-stock” for future projects and you should note these items down on your shopping list as soon as possible before you forget (also add a comment why you want these parts as it's easy to forget why you added a certain item).
At some point you will have to place an order for one or more critical components for a project, and there is nothing more annoying than not being able to make the order reach the minimum amount to qualify for free or discounted delivery. When that happens, you can turn to your shopping list and add in these items to bolster the order value.
At some point you will have to place an order for one or more critical components for a project, and there is nothing more annoying than not being able to make the order reach the minimum amount to qualify for free or discounted delivery. When that happens, you can turn to your shopping list and add in these items to bolster the order value.
Price breaks are your friend.
Screen shot from a suppliers website showing price breaks.
The above image is taken from a major electronics component supplier in the UK.
Component 11-0245 at the bottom of the list is a 100uf / 16V electrolytic capacitor and is a very commonly used component, so lets imagine that your project needs five of these.
The individual price is £0.042 so five of these would cost you £0.21, but look how the unit price drops to £0.0231 if you purchase between ten and ninety nine parts. Ten parts would cost you £0.231; this means if spend another 2 pence, you get five additional parts…. bargain.
Component 11-0245 at the bottom of the list is a 100uf / 16V electrolytic capacitor and is a very commonly used component, so lets imagine that your project needs five of these.
The individual price is £0.042 so five of these would cost you £0.21, but look how the unit price drops to £0.0231 if you purchase between ten and ninety nine parts. Ten parts would cost you £0.231; this means if spend another 2 pence, you get five additional parts…. bargain.
Storing your parts.
It won’t take long before you start to amass a collection of parts and you need some place to store them and more importantly, some way of storing them in a way that you can find them again.
The three big suppliers in the UK package their parts in plastic bags (usually zip-lock resealable ones) and this makes storage very easy.
Initially, you can probably use a large cardboard box to carefully store your goodie bags. One possible idea is to maintain a simple list or spread sheet that contains the part numbers, quantity and description of each bag. This mean that you can quickly check if you at least have some part in your box; finding one little plastic bag amongst a couple of hundreds other little plastic bags can be a bit of a challenge. As you progress and your stock starts to grow, you may want to invest in plastic storage draws and these are available from most of the on-line electronic parts supplies.
Again… shop around.
The three big suppliers in the UK package their parts in plastic bags (usually zip-lock resealable ones) and this makes storage very easy.
Initially, you can probably use a large cardboard box to carefully store your goodie bags. One possible idea is to maintain a simple list or spread sheet that contains the part numbers, quantity and description of each bag. This mean that you can quickly check if you at least have some part in your box; finding one little plastic bag amongst a couple of hundreds other little plastic bags can be a bit of a challenge. As you progress and your stock starts to grow, you may want to invest in plastic storage draws and these are available from most of the on-line electronic parts supplies.
Again… shop around.